
McVitie Weston valve collection, Marconi WT Co valve, type 5RR1L.F.(A)

Marconi WT Co valve, type 5RR1L.F.(A), (RMW/G3 - McVitie Weston number), by Marconi Wireless Telegraph Company Limited.
Marconi WT Co valve, type 5RR1L.F.(A), (RMW/G3 - McVitie Weston number), by Marconi Wireless Telegraph Company Limited.