I would guess that Western Gun Parts would be as close to a Brownells as we have,I tried Jerry a couple of years ago. At that time, he was not willing to sell short-chambered Mauser barrels. He said there are too many variations which make it hard to get the right barrel to fit a given rifle.
Before the State Dept. ban, I got a Schilen short-chambered M98 barrel from Brownells and it worked just fine.
As a comment, I think there is a good market opportunity for someone to start a Canadian business that parallels what Brownells does in the states.
Hugh