They are nose heavy due to the extra steel ( difference in the bore 38 vs 44 )
Armi San Marco's owner , was a son in law to Aldo Uberti... and some Uberti parts back then were on his shelves.
I ..myself, prefer the Army grips....
I have USPFA made 60 Army conversion in 38, It is according to USFA a circa 1993 Shot Show prototype.
I also have two 2nd Gen. Colt 1860 BP. The USPFA is I suspect, as the 2nd Gen's are , of Uberti origin.
I've owned one of these 60's almost 30 years, and it just went through transformation with an R&D Cyl. and Ivory content grips.
Being of Uberti origin, I opted to try the one piece kit grip for the Uberti.
They fit ...the Left perfectly, the Right just a smidgen small at the fore to aft, but not enough to worry about....
ALL that, just to say try grips to fit a Uberti.... Pietta will be to short top to bottom.