Two interesting clips which have recently been posted on the VBCW Forum.
The first is called Battle of the Machines - Longer Version 1930
It has some great pictures of loads of Vickers Medium IIs, from the Salisbury Plain Northland?Southland exercises. Clearly the crews preferred being on their tanks rather than in them where possible. No sign of lances with the cavalry. It is also particularly interesting to see the Carden Loyds with the QF 3.7" howitzer - it looks like two Carden Loyds per dun, one towing the gun on its tracked trailer, the other the crew in a tracked personnel trailer. It is particularly interesting to see the guns being loaded onto the tracked trailers for motorised towing - they seem able to get into/out of action very quickly.
The second is Tanks 1935
This has interesting shots of two Medium Mark IIIs and is very helpful for vehicle markings etc. At c3.15 it has what seems to be an MG-only armed command Mark II, which I have never come across before.
This blog provides images and information on interwar tank development by Vickers Armstrong Ltd. The photographs used have come from two works albums from Vickers Armstrong Ltd, held by the Beamish Museum and used here with permission. They also cover other vehicles including half tracks and wheeled transport.