I think in Canada, there are no concrete set values.
Generally, if it was a common non-restricted rifle, it will probably sell for 10-20% less than its live value (in the same condition).
Collector's Source tends to sit on lots of their guns for a while before selling them (because their generally more expensive than the average person wants to pay).
Now, if it would be a prohib then it will sell for more than its live value (in Canada). Chances are, if it is WWII era you will get a fair price on it. But, since there are not many of the same type floating around, the price would be determined on a case by case basis.