Hello, list Customs Officer here, For a 1947 car, all you will need is a bill of sale and the car's insurance print-out which doubles as a title in Canada. At the border, they will issue a form CF7501 which is valid in all fifty states to show your license office that the car has been examined by USCS and is in compliance. A '47 is exempt from DOT and EPA requirements. Duty is assessed at 3% of the first $1K and 2.5% on the remaining balance. US and CDN manufactured vehicles are exempt duty.
Please email me offline with any further questions. I can be reached at my office from Sun to Tue this week at 509 476 2955 or 476 2125. Regards, Rory Morrison Oroville, WA 1985 300SD 1982 300TD