The fourth link was the best but the guy building the miniatures still made up what he thought the flags would look like.
Yes, this is the problem with Hanover in 1815, very little information survives. I think only 4 actual flags are known to exist or have good descriptions. However basing conjectural flags on what is known we can arrive at some flags that are more plausible than others. I would certainly avoid ANY use of the British Union Flag in their designs; Hanover was a fully independent kingdom separate from the UK with its own long traditions and military history. The link to Britain is only because George III was king of Hanover when he was invited to take up the British throne as well.
Mike's link is a good one with some quite plausible flag designs, as long as we don't use the Union Jack.
This post from a gentleman named Rod MacArthur on the Warlord Games discussion forum (one of my links above) covers what we know in detail. From this and my link above as well as Grog's and your suggested pictures, Reb, I am sure NSD can produce some very acceptable flags:
Well regardless of whether there was any use of Union Jack quadrants on Hanoverian Naval Flags, or other flags in the post Napoleonic period, I am unaware of any evidence of such use on Hanoverian ARMY flags during the Napoleonic Wars.
The pre 1803 Hanoverian Army flags are well documented. The Infantry and Cavalry regiments carried flags with no quadrants, of any sort, on them. The flags had painted central motifs, different for each regiment, surrounded by a complex pattern of wreaths and scrolls. I have illustrations of all of these in UK, but I am currently in Spain.
The KGL carried British pattern colours, because they were units of the British Army. They would have undoubtedly considered themselves as Hanoverians, but this did not affect their status as part of a Foreign Regiment of the British Army (just like the French had Foreign Regiments). A modern parallel would be Ghurka units which are part of the British Army, but the Ghurkas are of course Nepalese.
The new Hanoverian Army carried a number of flags, as illustrated in both Terence Wise and Keith Over's modern books (both of which I have at home). A better, and older source, is an article (I think from the 1930s) by Dr Ottfrieid Neubecker. I attach an extract below (with apologies for my stilted translation):
The Flags and Standards of the Army of the Kingdom of Hanover 1813 - 1820
By Dr. Ottfried Neubecker
After the Dissolution of the Hanoverian Army by the Elb Convention of Artlenburg on 5 July 1803 followed the establishment of the King’s German Legion, whose history Schwertfeger has described in detail. Here also are the Legion’s flags and standards treated in enough detail. Very much less light has however been brought up to now of the history of the flags used by the subsequent King’s Army of Hanover. Although still yet everything could not be placed completely clearly, the results won so far may be laid down nevertheless here.
Already of the 10 "field battalions" which developed in the wars of liberation as basic foundations to the later army beside the King’s German Legion, some flags are well-known, although quite little.
1. Field battalion Roehl (raised in Berlin in April/May 1813), transferred in July as Battalion Langenrehr to Hanoverian services, then became Field Battalion Hoya from1814 - 1816. Its flag was presented by the Princess Wilhelmina of Orange, who was the wife of Prince William of Orange, a princess born in Prussia. It still exists and hangs in the Hanover museum. It is of black material, on both sides are applied different representations in white material. The front shows an upright white sword, behind whose blade a white oak ring lies, on the back stands a large iron cross with the white inscription:
MIT GOTT FÜRS VATERLAND
The 2.6 m long pole, that was painted blue, has the cloth fastened to it with a row of nails as well as a nail ring above and below. Into the 8 cm broad, 15 cm long point an Iron Cross is set. (Inventory Number VML 64221.)
2. Field battalion Calenburg. 120 x 120 cm the large cloth was formerly probably white, it is frayed and shows a dark green wreath, from a laurel and a branch of oak, enclosing an inscription; this is expressed on the back:
ZIEHT AUS
ZUM EDLEN
KAMPF
On the front:
KERT
HEIM MIT
SIEG
GEKROENET
Over the wreath is a very small label: Ao. 1813. The cloth is fastened around the pole with a row nails without braid. The spearpoint of normal form shows the royal monogram without numbers raised on both sides within an oval chain. The cord with the tassel is still present. (Inventory Number VML. 64222.) Figure 1.
3. Completely similarly a further flag is constituted, which has been wrongly attributed to the 8th Hanoverian Dragoons. It shows on the front on red circular ground the Hanoverian horse on a base facing outwards. On a circular ring is inscribed the old Hanoverian motto "QUO FAS ET GLORIA DUCUNT" (whither faith and glory lead) in antique writing. The reverse of the flag carries the classic signature mark of the King GR III under the British king’s crown in the disk, which here however is the base colour of the cloth, the ring surrounding the inscription (apparently formerly been red) is filled with a wave ornamentation. (Inventory Number VML. 64225.) Figure 2.
4. Field Battalion Lauenburg. This battalion had two flags, from which however nothing is known other than that they were presented to it by the Ratzeburger ladies and later brought in April 1813 to Bergedorf. (see the anonymous writing "the Field Battalion Lauenburg", Einbeck 1863, S. 4 and 5.)
5. Field Battalion Bremen. The city of Stade gave a flag to this battalion (after Aktenvermerk).
Also from the Landwehr battalions set up at that time there are still two flags.
1. Landwehr Battalion Gifhorn. The strangely small, originally 100 x of 80 cm size, apparently yellow, frayed cloth, from which only fragments are remaining, a large green oak in the centre, which is still relatively well preserved; also on the front the same silver Saxon Horse still is in quite good condition. From the inscription, but nevertheless the straight word "Gifhorn" is any longer much missing. Around the bar the cloth is fastened by means of a number of nails on a braid. The spearpoint is in an unusual form, however it is similar to that of the flag of the later Brunswick Lieb Battalion (III/92), containing the interwoven cipher of the King Elector George III in filigee work in the form
GR
III
The king’s crown standing over it is normal [ie Hanoverian], not British. Also the round cord with the simple, yellow tassel is still present. The pole is blue. The flag is said to have been at Waterloo in the [musket]fire. That is hardly possible, since in the obviously associated spearpoint (very small) the year 1816 is stamped. (Inventory Number VM. 16986.) Figure 3.
2. Landwehr Battalion Osnabrück. This white 138 x 160 cm, fringed cloth in a good state of preservation shows on both sides a blue inscribed ribbon, wound around a green branch of oak on the left and a green branch of laurel on the right and these two branches form a framework for different representations on each side. The inscription on the front states: "Landwehr Battalion" (above) - "Osnabrück" (below), on the back: "... at Waterloo at the 18th June 1815" (above) - "the patriotic warriors of Osnabrücks grateful citizens" (below in two lines). The front shows in the centre the very wide squashed red coat of arms sign of Hanover with the elegantly drawn current white horse, surrounded by a green palm and a likewise green branch of oak. In former times a crown rested on the sign but only so small outlining traces can be recognized, unfortunately not whether it was the British or the Hanoverian King’s crown. The other side is a large painting of Saint Peter, the city patron of Osnabrück, dressed into a long brown garb and a thrown-back blue cloak. The holy one holds two keys [Osnabrück district badge] in his right hand, while the left one leans on a large silver shield with the black wheel of the city of Osnabrück.
The cloth is fastened to the blue pole without a sleeve and only with a number of nails on a braid. The point, similarly the earlier Hanoverian ones, shows the interwoven signature mark of the king George III. in filagree work in addition, without the ordinal number, in whose place a small six spoked Osnabrück wheel is settled. The cord to this flag, which did not take part in any battles, is only present in half.
I have seen several of these flags in various museums in Hannover, when I spent 11 years in Germany as part of the British Army. I have also seen one which Dr Neubecker does not list, that of Kielmansegge's Field Jaeger, which does appear in one of the books by Wise and Over.
The important point is that none of the pre-1803 Hanoverian Army Flags, nor the new flags of the 1813 Hanoverian Army, nor the two Landwehr ones (even if they are post Waterloo), has a Union Jack quadrant on them. I therefore suggest that there is no evidence for any Hanoverian Army flag to use that pattern, nor of course would any Hanoverian unit use a full Union Flag (as British Regiments did as their King's Colour).