I really don't know but since it was well prior to 1968, there's a pretty good chance the majority were imported by Interarms. They managed to buy the vast majority of the war reserve No.4's in the 1980's from both the UK Mod and South Africans. I used to get a chuckle listening to all the exspurts at gun shows poo-poo them because they were import marked, (post 1968). The fact remains that the majority of No.4 service rifles released prior to 1968 were culled because something failed the gauging standards. They usually sported Britishicon commercial proofs too which no one ever complained about. Go figure.