Another thing you might try is replacing the striker spring. Many of these old milsurps have been handled by people who are less than knowledgeable about firearms and it may have hung on someones wall for decades with the striker cocked. Wolff sells replacement striker springs for Carcanos and several other milsurps.
http://www.gunsprings.com/index.cfm?...s&cID=2&mID=85