That instruction didn't seem to apply in Germany where the large Base workshops at Wetter and Verl (or was it Soest?) were combined RCEME and REME. certainly the Tank workshops were, for the Centurions and the small arms workshops. I know that the small arms and ammunition Ordnance suppplies and distribution were from pooled resources. On the basis that we had all marks of No4 issued from Ord, then so would Canada............
Our tanks always had (so said) Canadian made .300" ammo supplied for the Brownings. But I was told that this was because of the Canadian change to 7.62mm Brownings, we were using up the existing .300" stockpiles. Whether this is correct or not is a a bit academic, but..........
While the two different Sterlings were kept to Country, the magazines were often cross-supplied. In fact I've still got a couple. The Canadian ones weren't as good quality as the Sterling offerings but they seemed to work OK and plenty of the Canadian/UK Sterling spares interchanged andthey all went through the system.