Tracing an individual history is pretty much impossible based on the few surviving records. The best thing to do after reading the page on Rob van den Brink's website would be to put the details and photographs on this forum. There may be some clues in workshop rebuild numbers etc.
The E.R.M. system of two numbers two letters to numbers is still in use today. All Army vehicles have one. My WD B40 was issued with 84ET84. This system was introduced in the late forties I believe so all those sold off at the end of the war would never have been issued with one.
The RLC archive has quite a large collection B vehicle record cards and for a fee will do a frame number search to see if they have a card. I have found them quite helpful.
Cheers, Mick.