Bletchley Tube Wagon

Don't worry too much about the prefix letters before the 'B'. Others will correct me if I'm wrong, but I think BR built wagons were all given a 'B' prefix and this is the number that will/would have been on the wagonplate and also painted on the wagon side. Additional letters were then added before that when any were transferred to departmental stock, initially just the 'D', for departmental, generally meaning the P-way. The letters before the 'D' then identify other departments. 'K' for instance indicates the S&T Engineers. These letters would only be painted on the wagon sides.

 

I'll have a good look next week.