I've been casually looking for 450s for about tens years. I've only come across two that were available for a reasonable price. One was a spare out of a 70 sixpack RR that was scrapped long ago. The owner had kept the spare in his garage for 30 years or so. It was in perfect "survivor" condition and is now in my friend's 70 hemi Charger. I was with another friend walking through a junk yard when he spied and old polyglas tire laying in the dirt. He flipped it over, and low and behold, a nice 450 rim. I think the yard charged him $25. We found 3 H wheels in that yard as well.