If you cannot ever find one then you can have a fiberglass body built for you. What I do is look on www.collectorcartraderonline.com and a bunch of other sites on www.dogpile.com and search in there for cars for sale in your area. Go drive around for a day going down places even close to you, I have lived here where I am now for 4 years and recently wen't down roads about 15 minutes from me and found old cars that I never saw before and didn't think I would find... You would be surprised what you can find. Other thing is tell a lot of people what your looking for and ask them to keep their eye out for you. Way I found my car was I was at church talking to my guitarists dad about how I was looking for a hot rod and he knew a guy and I bought it and I never even knew my friends dad was into hot rods and now we talk about them all the time and go cruising in his hot rods.
Hope this helps at least a little.
Let us know if you find anything!