McVitie Weston valve collection, STC valve, type E.S. 755-1
STC valve, type E.S. 755-1, (RMW/D121 - McVitie Weston number), by Standard Telephones and Cables Limited.
STC valve, type E.S. 755-1, (RMW/D121 - McVitie Weston number), by Standard Telephones and Cables Limited.