Need help finding a bike. Need info too.

I want to find a 1970's CL450 Street Scrambler to restore for my father. It was his first bike when he was a young lad and my recent involvement in motorcycles has inspired him to ride again.

I know nothing about this bike. Is it rare? Am I going to have a hard time finding it, in decent enough condition to restore?

I live in the Calgary Alberta area and would prefer to buy from someone in the area, but I am interested in anything in North America.

Thanks Reddit :)