My "3L" rifle also has a '46 or '47 in the same location. Have also long thought it's a "pre-FTR marking" rebuild mark, or maybe the next level down from FTR. Seems more in tune with pre-WWII rebuilds, which don't seem to feature "FTR" regardless of level of rebuild. Could also be Canada specific. (?)
If remember what we have been told here previously, parts are only replaced if they are unserviceable. I would say it is "highly freaking unlikely" that the cocking piece, rearsight, safety lever etc. are NOT original to the rifle. Someone who was replacing those bits would not be likely to leave the rest of the rifle as it is, IMO, even if they could find those parts in a suitably worn condition.
You've got the replacement bolt, sear (lightened 'No5 pattern') and trigger one would expect for such an FTR.
Someone has gone to some lengths to scrub the paint and phosphating off.
Congrats on your fourth is it? ;)