My current boat was Canadian owned, but US built. 1942 Wheeler, 83' cost me $12.50.
The customs people like to know what's coming in advance. I notified them by email and that day by telephone. They were very nice, met me where I docked, and even filled out the papers for me. And my papers were a mess. The Canadians had the build date and builder wrong. I had a stack of papers and email copies while the US documentation was pending. And it still only took a few minutes.
At the time the boat went from US to Canadian ownership it was totally rebuilt. Only the hull, shafts, and rudders were original. The yard that did the rebuild was down as the builder. Saving grace was the US number was still in the main beam.