You're probably going to have to head Stateside, because there isn't much left up here anymore. Here in Alberta, I haven't even seen one of those cars in about 10 years now. The last ones in our wreckers out here got crushed about 15 years ago. And Ontario with it's salt problem, don't imagine much survived, those cars rusted like shipwrecks.
Going state side isn’t happening any time soon, keep checking kijji, riviera’s/Canada in your search. It’s not like you are looking for fenders so you may get lucky
Rob keep your eyes peeled on kijiji I usually see stuff for the Boattail Rivs come up quite often. There was a guy in Hamilton with a bunch of Boattail parts not long ago.
I will be parting out a 72 Riv. What exactly do you need? FYI shipping to Canada will be pricey but I'm not trying to hustle. I'm in LA area of California.