Could you PM me where you got the information from, especially year and the Fiat chassis bits?
I found this car in literature as the AFM Super 2500 Cabriolet, a one-off from 1951.
I'll try my best; I struggled to find it again last week but hopefully I saved the site as a favourite, but on my computer at work.
I'll have a look on Monday (I can log in from here but won't have the time what with the Italian Grand Prix and the pre-1980's TVR meet tomorrow..)
The site I found it on last week might not be the original one I got the picture from however, as I have a recollection that it also detailed who the car was built for, an aristocratic gentlemen; I have been unable to verify that though.