How to tell a genuine Fiat Abarth 1000TC

I'm not a real expert on this. As far as I know, the shell of a Fiat 600 Sedan and the shell of a Fiat-Abarth 1000TC are identical. All of the differences are in the equipment, so any 600 Sedan could be made into a replica that would fool just about anyone. About all you could rely upon would be clear, airtight provenance and continuous history from day one. On a street car, that might be possible. On a race car, it would be a nightmare.

Even if you found a car that claimed be have originally been sold as an Abarth, it could have been repaired/"upgraded" over the years with incorrect parts, and now appears to contain bogus components. For instance, if it now has front disc brakes from an 850 (that do not fit inside the original 12" wheels), who's to say that the original/correct disc brakes aren't in a box somewhere?

I believe there is a stamping on the firewall in the engine compartment next to the ID tag that indicates an Abarth origin, but even that can be faked. The ID tag itself proves nothing.