The last photo posted is one that I have labeled as a Cisitalia-Mercury XF808. That would make some sort of sense to me, anyway, since the Merc motor would have been a flathead and I'm used to seeing XF representing a flathead motor.
The other thing that I noted was the statement about it being on a Thunderbird chassis. I don't think this is right, since the first Thunderbird appeared in 1955. So having chassis to build on in 1952 or 53 doesn't make sense. Upon further review this post :
http://www.autopuzzles.com/forum/index.php?topic=11375.0 says that it was based on a Fiat 1900 chassis with "the inevitable manifold with two Zenith carburettors [sic] and the exhaust system with separate pipes." Not written by an American hot rodder, that's for sure. But maybe it refers to the 505, not the 808, which seems to have been built using the Fiat 1900 motor as well as the chassis.
On another site with fairly decent accuracy, but full of typos says that the only cabriolet version (see attached photo) has a "law enforcement" (we'd say "police interceptor") motor of 312 cubic inches and a 3-speed automatic gearbox. The issue here is that the 312 "Y-block" motor was first available in 1956, while the "Ford-o-matic" transmission was sort of a 3-speed (1st gear only used when manually selected) so if that's what it really has, I'd say that it got the engine and transmission out of a 56 T-bird. However, that information is contradicted on a different site which claims that it has a Ford 6-cylinder motor.
I haven't been able to see any photos of any of the Cisitalia Fords' or Mercurys' motors. So I can't verify any of it. But my guess would be on the flathead V8 for both of 'em. They were much shorter than the I6, weighed about the same and made more power, especially with the "two carburettors."
If someone has photos of a Ford 6-banger in a Cisitalia, I'd love to see it.
