They weren't rusted on. I wish it was that simple. When I first saw the car before buying it the car had no wheels on it. The owner agreed to make it a roller and put on the 13s. I came back and picked it up. It's clearly not seating where it should. The idea that these may have 10" drums from a 66 for 14" seems plausible. Whether or not the hubs are the same outer diameter is the question. I'n not sure if 14s and 13s for the Valiant have the same center hole diameter, I don't have both to measure. With all this the 13s fit rear axle centering stud. I guess it is possible that someone during its life put 66 drums on the front and maybe 14's all the way around, leaving the rear to be lug centric. I do know the front drums have been changed, both are right handed thread. Its not likely that I can get to it this weekend, but I'll pull a drum and measure hub and drum diameter. Maybe Charlie_S and I can then compare measurements here. Thanks everyone.