McVitie Weston valve collection, Marconi Osram valve, type D.E.R.
- maker:
- M-O Valve Company Limited
Marconi Osram valve, type D.E.R., etched S6976, (RMW/C23 - McVitie Weston number), by M-O Valve Co. Limited.
Marconi Osram valve, type D.E.R., etched S6976, (RMW/C23 - McVitie Weston number), by M-O Valve Co. Limited.