I just finished working on a Pietta Paterson. Corrected the short arbor, made a music wire spring for that goofy folding trigger, tuned the hammer spring. It took two men and a boy plus a hydraulic jack to cock the hammer. Also thinned the left bolt leg as it was thick and clunky. There is not much that can be done to the Paterson as far as tuning is concerned. I did find an interesting problem. This pistol would get very hard to cycle eventually locking itself up. The design is 4 pivot screws, hammer, trigger, bolt and a sear link. The sear link and bolt pivots have no heads on the screws. The bolt screw is just long enough to support the bolt with no support on the inner end. If it's turned in until it stops the pistol is locked up. The bolt pivot screw will hit the trigger/sear link and bind it solid. This particular pistol had a habit of turning this screw in each time it was cocked and eventually locking up. Once that problem was solved it became a lot more reliable. I wouldn't consider a Paterson a daily driver due to design limits and being somewhat fragile. As an occasional shooter it should be fine. There's a reason the design didn't stay around long.