I don't worry to much about spare tires on my CMPs and here is where the jinx comes in, in the nearly 30 years of driving them I have never had a flat tire.
Two of my trucks have spares though if you look where they are carried I'm not sure I could get them down by myself. The HUP carries it's spare in the side rack (see
http://www.mapleleafup.org/forums/sh...ad.php?t=12207 post#11) and my C60S carries it's spare in side the radio box.
For years I carried a spare tube in the truck along with the tire irons to change it until I notice that the tube in the box had dry rotted.
As to finding them I'm sure some one in Canada has a spare one sitting around and that the real issue is the logistics of getting a 300+ lbs tire and rim moved.
Good luck with your search.
Cheers Phil