IMO: FR means, field armorer repair.
http://forums.gunboards.com/showthread. ... -Buttstock
It was sold out of service by the British, so was up to their standards when surplus'ed off (Birmingham proofed). The Savage hand guard is common, as both N. American factories, shared parts. If the stock is not original (it looks good from here), the FR might refer to it's previous prom date. The Canadian's usually didn't mark their wood, so it might be difficult to determine if the wood is original.
You want to do some reading:
http://forums.gunboards.com/showthread. ... Libraries-(Index-of-Articles
"Self-realization. I was thinking of the immortal words of Socrates, who said, "... I drank what?"