>I think you had to be a Canadian to win the Canadian
>Championship in the 1970/1980s when JB had several
Doubtful that the championship required any residency when JB was a regular competitor in Canada. It was more likely the way it is now; you must have a CARS licence to score CARS points. He did not score points when he won Charlevoix 2002.
>Has the Canadian situation changed?
Better question is when will the SCCA situation change to honor CARS licenses with having to buy SCCA memberships?
There is no Canadian situation and probably never was. Paul Choiniere, Carl Merrill and Mark Williams (twice) have won overall CARS championships while US citizens.