What is this Proof?

[Morning Wood]

OK...enough guessing... This is the C Broad arrow Canada marked it's weapons with. The barrel ring is a poor mark that was embellished and then re-struck. The butt heel is the S of a small marked butt. The others are all C Broad arrows...the South Africa mark of course is clearly something else...

In case you doubt me...I'm Canadian...

Regarding the pic in the original post,

The mark closest to the trigger guard is of course a "B" imposed over an "L", which as we all know is the wartime Longbranch mark.

The roundish one below it is the mark for postwar Canadian Arsenals Limited which was a govt owned enterprise that took over Longbranch after the war. Looking closely at that symbol, you should see that the round part is actually a stylized "C" with an "A" and "L" integrated into it.

Beautiful rifle BTW.