Hello - sorry to be the bearer of bad news and cut you short after your first post, but as far as I know, the Uno didn't come with an electronic speedometer (someone, please correct me if I'm wrong). Even the Uno Turbo with optional digital instruments had - believe it or not - a normal old speedometer cable going to the cluster!
There are other FIATs the same age as the Uno that did have electronic speedometers. The most common is probably all models of the FIAT Tipo. I think the sender should fit an X1/9 gearbox - the gearbox is different, but the sender is the same shape and size (from memory). I've also fixed electronic senders in the FIAT Croma (really thin on the ground these days) and I think they're again the same, because I swapped a drivegear and collar from an old 128 gearbox into a Croma gearbox. The reverse would therefore likely be possible as well. Other cars with the same gearbox as the Croma include the Lancia Thema... and the Alfa 164. You have a lot of 164s in the USA, so maybe that's a good place to start looking? Has to be a manual transmission 164 though - auto is made in Germany and completely different.
-Alex