I recently picked up 2 lk-93's to clean up and salvage parts for a couple I've had for years. After pulling both triggers out, I noticed they are virtually identical except one is stamped "made in US Timney" with one adjustment screw in the front. The other only had a "Z" or "N" stamped on it but had 2 adjustment screws. All my others only have one adjustment screw. Any insight to what the 2nd screw is for before I go to playing with it?