I don't know the rules of shipping bikes into canada so I have no clue there.
frome the pics you have it really just looks like the bike you have locally is more dirty than rusty. 000 steel wool will clean up the rust on the chrome, the frame unless it looks like rot (and you'll know because it looks unsafe) then I wouldn't worry about it. Rustoleum Stops Rust paint in a spray can help you touch it up if you are that worried about it.
The big problem with cb750s that have been sitting around is the brakes begin to stick and eventually lock. If this hasn't happened yet then you know the bike gets regular use or has been stored properly.