Thanks. I do check Craigslist occasionally. I actually have picked up some tires that will work for me in both the 10x16.5 size and the 12x16.5 size. The rims I have are for 12x16.5, but when I put a 12x16.5 tire on there is about a 3" gap between the tire and the rim. I haven't been able to get it to bead up. My son wants me to use the lighter fluid method, but I'm not willing to. At least not yet.
These tires might be too stiff for this trick but sometimes putting a ratchet strap around the center of the tread and cranking it down can get the sidewalls to spread out a bit.