God that's heartbreaking to see
No, actually it isn't heartbreaking to see. If all of the rifles used during WWII were left intact, they wouldn't command the prices they do today.
That rifle is restorable and with a bit of effort and patience all of the appropriate furniture, etc can be accessed.
OP, your uncle took a great rifle, that he may or may not have brought back. Such rifles could be purchased by the crate, right up to the mid seventies, with all accessories for around $20 Canadian. Enfields and Lee Enfields were cheaper. Krag carbines were sold at Hudson's Bay and Marshall Wells for $17.50 Can.
It doesn't have a duffle cut on the stock, so if it was brought back as a souvenir, there should have been some documentation, which could have been lost. I've seen hundreds of similar rifles since the sixties.
Every gas station, hardware store and even some rural grocery stores had them. There were huge businesses in Europe, Canada, US etc that cut those down in exactly the same manner as your rifle. All sorts of after market accessories were available at reasonable prices.
I've been duped myself by the story on more than one occasion, sometimes embarrassed later.
If it weren't for rifles such as the one in your pic, many Canadians wouldn't have been able to afford to hunt or shoot. Surplus ammo for that rifle was cheap. Shipping was usually more expensive on a crate of ammo than the cost of the ammo. If you bought 5 x 880 round crates, they cost $40 and it cost $42 to ship it by rail. Ask me how I know.
That's a fine inheritance. Leave it as is and shoot it. Enjoy. Present value on that rifle is around $400, only because it's restorable.
Cartridge it's chambered for is 8x57 Mauser or 7.92x57 (they're the same) With proper European ammo, it's right up there with the 30-06 in effectiveness on game.