The bus, in post #574, is of interest. In 1949 (assuming the date to be correct) it is still in wartime livery - dark roof and rear windows. Birmingham was usually on the ball where liveries were concerned and I suggest that most daily operational pre-war buses would have had the new style khaki applied. It appears, although looking somewhat jaded, to be a 1937 - 39 Daimler product.
It is a SPECIAL and I suggest a spare vehicle, maybe used as a snowplough or other non passenger service vehicle. There are posters in the windows and I wonder if, given the 1949 date, it is being used to educate passengers about the forthcoming closure of the tram route 6 at the end of December, 1949. This tram route was not replaced by a new bus service but incorporated into the existing 33 bus route.