They will bolt on, but they are not “interchangeable” in any meaningful sense. Here’s what you run across:
Screw patterns line up. Threads are the same size. But size of the screw heads is different, so you end up ordering a complete new set of screws.
Cylinder frame widths are different. Pietta’s revolver has a more dramatic taper to the front. A Pietta TG won’t properly cover the bottom of a Uberti cylinder frame. Vice versa, you’d have to narrow out the edges on Uberti TG.
Uberti’s cylinder frame seems to be a 1/8 inch larger vertically. Pietta’s TG / BS go on a bit kitty wampus as a result. The other way around, I recall the Uberti TB / BS gapping on a Pietta frame.