There is a thread on HMVF about Army Kinematograph Service Films.
Some were available on VHS produced by Editions Audiovisual Beulah in association with Vintage Commercial Vehicles Magazine in the late 1990s. They are no longer stocked, and were not done as DVD.
It seems they are available from the IWM on DVD but are pricey, and of course are not to be copied.
There is a series including Scammel Recovery, Armoured Recovery, Beach recovery and others about motorcycles, armoured cars and various training topics.
Rob