Merc, if it ain't broke then don't "fix" it!


Liam, from what I saw while glancing over your pics it looks to me as though you have a BSA (Birmingham Small Arms) rifle. What we call a commercial version. BSA was a prime contractor to the MoD and was not a Royal Ordnance Factory.
In addition to contract manufacturing for the British government, they also made rifles for foreign contract and civilian sales. You have one of those!