The Asset Codes in the order they are written are defined as:
2855-0711 Trailer, 3/4 Ton, 2-wheeled, Cargo, Pressed Steel
5656-0711 Trailer, 3/4 Ton, 2-wheeled, Generator 3.5 KVA Single Phase
2855-0711 Trailer, 3/4 Ton, 2-wheeled, Cargo, Pressed Steel
2852-0747 Trailer, 3/4 Ton, 2-wheeled, Cargo, Various makers
I can only assume the final code change was the the Army were no longer interested having a sub-category that defined the maker.