Incidentally it was a WW2 era 2 pdr anti-tank cartridge case stamped "RM/L" that I posted on BOCN and was subsequently identified as made by Richard M. Lord.
Graeme
Any chance of the monogram being RH/L? Ruston & Hornsby of Lincoln made cartridge cases in WWII. (The convention in monograms tends to be that solidus followed by a letter designates a location, be it a city or country.)
Tom.