Maurice
In the Ministry of Supply book of Wheeled vehicles, there is reference to your trailer, described as "trailer 5 ton 4 wheeled laundry ccs" which lists the equipment found inside this trailer. It is very brief, the only difference being, it states the tyres are 10x 50x 13. But these could have been changed. I would suggest that you contact the RLC museum Deepcut, as it would appear this equipment was operated by RASC personnel.
Wally