I thought since they were made in Italy they all had metric threads.
Nope. The Uberti 2nd Dragoon and Walker, the ASM Walker and the Pedersoli and Pietta/Navy Arms 12 ga SxS shotguns all have nipples with 1/4x28 threads. The Uberti 1861 Navy and Cattleman percussion revolver and the Euroarms 1860 Army have 12x28 threads.
At least mine do.