The Sullivans

I remember the fist episode where Kitty alights from a W class tram on her way home from school. It was set in 1939 but shot in 1976, I wondered if the producers did anything special to choose the tram that Kitty rode on or just boarded the regular service W class which were still running at the time?

Probably the former because they would have done retakes and made the tram go back and forth.