Thanks for the replies. The code most often used by the test stations is 115202 which seems to be right for my RMs. Will try and make sure this is always used so the results are comparable. They sometimes ask if the vehicle was first used before 1968 but this doesn't seem to affect the pass efficiencies for class 6 tests, though I think it might for class 5.

My bus number (if any): RMs 238, 471 and 2213, GS17

I suspect the difference in years is for the handbrake efficiencies, from memory the handbrake on a class 6 must "stop the wheels turning" on test on a pre-1968 vehicle. I can't remember what the class 5 regs say!

My bus number (if any): RML2532