Giday, John. The process is relatively simple. I'm not trying to nit pick here....but the details are very important. If you are talking about a replica speedster here, and you didn't say that but you likely are, you are not importing a car, you are importing a REPLICA car and as such, it must have been built over 15 years ago. You must be able to prove this. If a replica vehicle is titled in the States as a 1973 VW for example, it will not qualify for import into Canada. The Canuck Border minions will know ( should know ) that it is a replica and it must be imported as such.
That being said, you'll have to find a replica with a clean title and proof that it was built over 15 years ago. If you do find this, you can then buy the car, collect all your documentation and submit it to the US side of the border crossing of your choice 72 hours prior to you attempting the crossing with the car. After 72 hours have passed you can approach the same US border crossing location and go through some paperwork for you to EXPORT the car from the US. No charge for this.
With the vehicle and all paperwork in hand you proceed to the Canuck side and do some paperwork to IMPORT the car into Canada. All your paperwork must be in order and the sales receipt showing the value of the car must reflect a close resemblance to what the Dork at the border thinks it may be worth. If he gets onto Ebay for instance and sees some overinflated $$$ examples, and you bought a lower priced item like I did, you may have some difficulty convincing him of the price you say you paid for the vehicle. You might do well to have a few other ebay sales examples on hand of what cars like the one you bought actually sold for.
When I imported my car four years ago, the Canuck border people charged my the Federal tax and when I went to get the car licensed in Ontario, the Provincial tax was charged. You must have a safety check in hand as well as all the other paperwork when you go to the License Bureau here. They will issue a new ownership ( title ) for the car in your name. You'll need proof of insurance there too.
The RIV is not involved in this process. The 15 year rule is still the law.