OK, thanks to everyone for all the help & empathy, but I've got to say I feel like quite the fool.
Apparently I've been fighting the wrong battle all along. When I talked to Transport Canada today, the guy briefly mentioned that I should check the recall letter again. He then talked for about half an hour about how to try to contact the SSCC and Polaris engineering group to get the letter of compliance, and I was so intent on trying to take it all in, I forgot all about his remark about the recall letter. Finally I remembered and took another look at it, and lo and behold, the wording sure looked like the letter of compliance I've been chasing after so hard. I called the RIV to verify, and sure enough, it does double duty as recall letter
and letter of compliance (only thing it's missing is the date of manufacture, but I have the MSO, or something else can apparently be printed off by the dealer). So I've been chasing after something I had right under my nose all along!
So now the hurdle to overcome is that the VIN as stamped by the manufacturer is gone. Tri-City engraved the VIN back on after they replaced the tunnel, but when I tried to take it across on Friday night, the customs guy noticed it was done with an engraving pen and sure didn't like it. However, I should have a pretty good chance because the tunnel was replaced by a dealer and the replacement was fully documented. Tri-City is willing to write a letter stating where, when, how, why, and by whom the tunnel was replaced. I'm going to check further into what's needed tomorrow. From talking to the Superintendant of the Coutts Crossing (real nice guy), I believe I can get some sort of a file or confirmation # so I don't have to go through all the explanations again when I get there.
I know, I know, everybody's thinking I should quit being so anal and just go try again, but now I'm spooked, and when I drive the 7 hours down there I want to be nice and relaxed, knowing I'm bringing both sleds home.
Thanks for all the efforts of people trying to help with the compliance letter, and I'm really sorry about your time & energy wasted on this wild goose chase!
Tim