Wanted: Rallye Centers 5 on 4 or Good Scrap Yard Locations

I was (also) going to suggest ebay. You might also try Wheel Vintiques. They won't be "original/NOS, but they might have a decent replacement.
I have also bought stuff from Dave's Rally Wheels in California. Also, Jim's Auto Parts has a lot of stuff. I would (personally) stay away from Layson's.....They are pricey, slow, and don't communicate very well.