McVitie Weston valve collection, Marconi WT Co valve, type E27
Marconi WT Co valve, type E27, marked 45, (RMW/H64 - McVitie Weston number), by Marconi Wireless Telegraph Company Limited.
Marconi WT Co valve, type E27, marked 45, (RMW/H64 - McVitie Weston number), by Marconi Wireless Telegraph Company Limited.