McVitie Weston valve collection, BTH valve, type A.T.40
BTH valve, type A.T.40, marked 7266, pinch marked A, (RMW/J93A - McVitie Weston number), by British Thomson-Houston Company Limited.
BTH valve, type A.T.40, marked 7266, pinch marked A, (RMW/J93A - McVitie Weston number), by British Thomson-Houston Company Limited.