So far as I am aware, stamping the unit details on the weapon was never authorised simply on the basis of where would it end! At least with a marking disc you could use both sides and then new and so on. To be honest, knowing how strictly controlled the world of Armourers was pre-war, I douibt whether any Armourer, Arms storeman etc etc would unit mark by stamping. The quartermaster would go ape.......... Wartime was slightly different - as it usually is. Brian Dickat BDL
Ltd in SC has a little booklet that details the marking detail taken from the Equipment Regs of the era. It does list a load of Royal Artillery unit marks.
RAF issues of this revolver were slightly different as the RAF purchased their own and the initials RAF were engraved (not stamped) on the body prior to supply (presumably at Enfield ?) to the RAF