Stupid question here, but when you looked at the rear rims, the outer dual is facing inwards so the lock rings would be facing each other. Is that what you looked at???
Also 10 lug Budds, motors, etc..., wheels are different then the 5 luggers. The 5 lug hub I "believe" is wider then the 10 lug hub. Also for positive the studs are quite a bit bigger and wont fit a 10 lug without machine work. The 10 lugs I have are about pinky size studs, while the 5s are about thumb sized.
Of course this all may be different because were talking Canada here!

3B should know this.
Jeff