I thought I had answered this before.
However, trams were not fitted with blinds, but some did have mesh fitted to the glass. The 'blinds' seen in car 3 were fitted with in apparently canvas as the tram had no windows due to the oil bomb which hit Miller Street depot on 9/10 April, 1941, which destroyed 24 trams and damaged many more of which car 3 was just one. This was a temporary repair until board or new glass could be fitted to replace the lost windows. It was essential that BCT got as many trams back out on the tracks as soon as possible in order for workers to get to and from their work places. Car 3 survived until 1949 when the Perry Barr route was replaced by buses. Despite the Luftwaffe the tram manged 46 years service the the Corporation.