When I worked for BCT Head Office in Congreve Street, I and a colleague, Ray Bednall, did Lost Property audits at Miller Street. This was in the late 1950s. The Lost Property audit was required by law under the Passenger Transport Act. We did similar audits at Tyburn Road, but that was to match stock discrepancies between the manual stockkeeping system and Powers-Samas punched card system, and to supposedly stop thieving of common household items like soap or small nuts & bolts. It never did, of course!
We would prepare a list of a dozen thieveable items and add one of two large items that no wanted to half inch like chassis members, and do this once a month. I don't think anyone really took it too seriously and it was all done fairly jovially. When we got back we would just adjust the stock records accordingly. At that time the main Social Club was at Newhall Street. All garages had their own canteens and I can't remember a Social Club across the road at Miller Street.
Maurice