I'm not sure there all that many C60 series CMP around, maybe out East but not that many in Western Canada, have not seen to many on the forum restoring C60's, there are a few trucks around but I do not know of anyone with an extra tire and rim ? Check with Dave Pope, he may know if Mike or Ken Heiberg in Saskatchewan still have a few, they had a C60 Tipper for sale.
www.canadianwheel.com will make you an exact duplicate rim from a pattern. they are located in Vancouver, Calgary and Edmonton.