Up until 3rd June 1946 / 11th June 1946 the only parts that needed numbering were the " 3-Bs" pressure bearing parts (Barrel, Body and Bolt). Up until then each manufacturer could number other parts if they so wished, there was no requirement.
From the date of this LoC the forend and magazine was 'added to the list' and, any No4's coming in for repair, maintenance or servicing SHOULD have had the forend and magazine numbered during the repair.Information
Warning: This is a relatively older thread
This discussion is older than 360 days. Some information contained in it may no longer be current.