The problem is that apparently when Rossi was making the 92 Puma they reverse engineered the guns and MAYBE used the same thread screws as the Winchesters. LATER once Rossi/Braztech owned the company they apparently rebaselined the guns and changed the threads to metric.
So if the gun is older the parts may fit, if the gun is newer then it is less likely that the parts will fit.
The Winchester threads will NOT be metric.
I DID find this bit on another board:
https://forums.sassnet.com/index.php?/t ... ze-needed/"Was wondering if anyone knows the thread size for the trigger spring screw on a Rossi 92’? Thank you." Deuce Stevens SASS#55996
"3.5 x .35 metric Same as the cart guide screws" Nate Kiowa Jones #6765
That's a bit of an odd size. Might find them at the hardware store. IF all you can find turns out to be stainless that may be a problem if the receiver is stainless since a stainless has a tendency to cold weld.