I bought 2, and my friend bought one. Neither had 2 screws included. I asked the salesman at Sportsman's Warehouse, and he said the guns like this and others with black powder frames came with only the thumb screw. So, maybe they came both ways. Mine and my friends were recent purchases.The Cimarron I bought (new) had the thumb screw installed in the gun, and the standard screw was in a piece of styrofoam.
In the first post you stated it is a Pietta. My TRs are Piettas. Uberti sent you a screw?Update - emailed Uberti, provided them the specific firearm info needed and a normal screw arrived a few days ago in the mail under warranty. Very pleased with their service.