panzer

That is a PzKw IV (Panzer Kampf Wagen 4). Was a middle class tank.

The serial number may read 9177, in March 1919 it was transferred from Central Workshops to Stores, no other information exists on this tank. Source: sites.google.com/site/landships/home/lists/mk-v-tanks/910... The reference to cavalry may be accurate, the British kept their cavalry in being until World War Two, the Household Cavalry only gave up their horses in 1941. Mounted cavalry saw great deal of action in the last 100 days of WW1 when the allies were pursuing the retreating Germans. The British heavy tanks were designed to crush wire and silence MGs and thus are probably best compared to siege weapons, though they occasionally fulfilled the shock role of heavy cavalry on the open battlefields in the later half of the 100 days. Some consideration was given to using tanks in the traditional exploitation role of light cavalry, thus the British built the Whippet and the French the Renault FT17. The light cavalry's scouting role had been filled by the RFC / RAF. Tank crews did not apparently regard themselves as cavalrymen, first world war tank units were designated Companies not Squadrons (I don't know if this is still the case in the RTR). Cavalry terms were presumably only adopted by British tank crews when the British cavalry was (reluctantly) mechanized in the 1930's. Tank crews came from a variety of units, some may have been cavalrymen but they were apparently not overrepresented.

This is a partially stripped or damaged Panther ("Mark V"), perhaps variant E or G.