Re gravel ...I'd love to see a pic of those strange Ham River sand and Gravel Trucks....by 1968 a co. called Hall and Ham River were taken over by Ready Mixed Concrete (RMC) a multinational with interests in many Thames Valley land deals (I think Thorpe park was one of theirs)
Hall Sand & Gravel - that is ringing loud bells as the company that took over from Ham River (either bought out or got the contract). Red Bedford TKs now sound familiar - I think??
The AEC half cabs were not ex military but bought new - my uncle worked at AEC and there was an article about them in a staff magazine he gave me.