I imported a 1982 380SL a year ago and the process was a cinch. Very straightforward.

I drove across the border myself. Suggest you avoid highly congested times to reduce your wait time. Arranging temporary plates and insurance will take more time on an older model than figuring out the customs regs. In my case I was able to convince Ontario MTO to issue a 10 day temp plate so I could drive the car home and put it through its Ontario safety inspection before permanent plates could be issued.