Unfortunately, it isn't just the year. Short answer, they aren't legal. And the definitions of why are bewildering. Forgive the mire below.
From the Canada Criminal Code:
""firearm" means a barrelled weapon from which any shot, bullet or other projectile can be discharged and that is capable of causing serious bodily injury or death to a person, and includes any frame or receiver of such a barreled weapon and anything that can be adapted for use as a firearm."
So even the parts by themselves are prohibited (need a license). But they aren't functioning, right?
From the RCMP:
"Even if an imported firearm has been deactivated, it will be treated as an active firearm until it is in Canada and the deactivation can be confirmed by a licensed gunsmith. To import such a firearm, you need a valid licence allowing you to import that class of firearm and you need to register the firearm. Once a licensed gunsmith in Canada has confirmed that the firearm modifications meet Canadian deactivation standards, the firearm may be deregistered."
Well, I guess you can get a replica then, right? Nope. Replica firearms are also prohibited in Canada. Replicas firearms are defined as things that aren't firearms but are intended to closely resemble real-world models of firearms. Replicas of antique firearms are allowed.
So you're clear on the Mauser? Nope. The RCMP says antique firearms are defined as:
"Any firearm manufactured before 1898 that was not designed to discharge rim-fire or centre-fire ammunition, and that has not been re-designed to discharge such ammunition."
But, you've seen airsoft for sale in Canada, and they look like guns, right? Well, air guns above a certain muzzle velocity/energy are prohibited "firearms" and need licenses and such. Air guns below a certain muzzle velocity/energy are not prohibited firearms and don't need licensing unless they are also replica firearms. So those clear plastic low-velocity guns are fine, but if you paint it to be realistic, that's potentially a criminal act. If it's realistically painted, but scaled smaller or larger, then it's maybe fine. But that presumes the viewer knows the correct scale well enough to not be threatened.
All of this is muddled by the fact that some people have imported denix mausers and cite that as proof. But that's of no help, because packages are checked by Customs randomly, or are subject to the individual officer having a specific reading of the Criminal Code.
I ordered one of the Tomenosuke Blade Runner blaster kits and received it, but I did so with the accepted risk that I was in for a fight if it was looked at by a particularly zealous Customs officer. Because due to the loose definition of "firearm," the frame alone can be considered a "replica firearm." And even though the blaster itself is technically not a replica firearm because it was not made to resemble a real-world weapon, to an untrained eye, it sure looks like a gun. And in Canada, if you use a toy to rob someone and they believe it's a gun, that counts as a firearms offense.
Fun, eh?
Edit: I reread the last part and it sounds weird, like I'm complaining about not being able to use replicas in robberies.:facepalm
By "fun" I mean how the CC is all but blind to recreational/prop uses of replicas and parts, and pretty much assumes the only use they have is for criminal purposes.