There's a 28 (4F565) on display outside Crane and Tractor (CAT - who are a Fiat-Allis dealer : ) in Columbus. It's complete other than the seat leather and lever knobs but not in excellent shape / not operational. It has a pto shaft. Next to it are what looks like an OC6? and a K model? Allis Chalmers that has a belt pulley.
There's also an HD41 on the lot - didn't realise that F-A made them quite that big. I'll take a camera with me next time I go past.

Cheers,
Neil.