Many and varied arms were collected and dropped for the Resistance, and don't think anyone had the time or inclination to mark them in any way.
2 Webley revolvers of my G-fathers were handed in to be dropped for the resistance, one a .455" pre 1900 so likely a Mk 1, 2 or Maybe a 3, plus a .455" Webley Fosberry he had from his time in the Special Police in WW1.
Often wonder what happened to them.
This was back in Yorkshire.