
McVitie Weston valve collection, Marconi WT Co valve, type TT11

Marconi WT Co valve, type TT11, (RMW/Y624 - McVitie Weston number), by Marconi Wireless Telegraph Company Limited.
Marconi WT Co valve, type TT11, (RMW/Y624 - McVitie Weston number), by Marconi Wireless Telegraph Company Limited.