I am looking for information about a BSA WD B40 with the registration number 00 SP 77 which I have discovered was an Army registration number used for 'Special Projects' vehicles. These vehicles, I am led to believe, were tested and assesed at the MVEE (Military Experimental Engineering Establishment) Chertsey. Were vehicles with these 'SP' registartion numbers issued with Key Cards and, if so, where would I find them?