I have since found out the following details about it;

As correctly identified it’s a Bedford SB special with Wilsden bodywork and one of only around 27 made. Reg no OVE 400 and first registered on the 1st January 1956 – the crash happened on the 29th February 1956 in Cambridge near the junction with Brooklands Avenue, I also have the drivers name as well. It was eventually retired in 1971 and went to Cambridge fire station to be used for driver training. And according to DVLA records it appears to be still around somewhere – although untaxed at present.
Would love to know where it is!?

Rob