It was manufactured by Armi San Marco (ASM), not Uberti.
There will be two Italian proof marks at various places on the gun; one consists of the letters PN under a 5 pointed star inside a garland, the other a shield under the same star/garland.
There will also be either a two letter code inside a square box or a roman numeral-like code without the box; this identifies the year when the gun was proofed by the Italian proof houses.
Here's the date decoder ring:
