I rediscovered some 500 related documentation today. I bought a load of bits and other paraphernalia some years ago in two job lots. Some quality A4 art prints, a 6 page laminated article on Indie 500s , pushing tuning and your wallet to extreme limits. Then a laminated double sided Italian brochure which lists 4 models that I did not know about. The Fiat Giannini 22 HP 500 TV, 27 HP 500 Montecarlo, 28hp 590 GT and the 35hp 590 Vallelunga. I can post some more pics and let me know if you are interested as happy to post.