Well, I just picked-up the problem 336 from the gunsmith. He fired it before tear-down and experienced several misfires. When he took it apart - no broken firing pin; no broken springs; everything tight and proper. All he could do is clean it and polish some of the parts. He also polished a slight taper on the end of the rear half of the firing pin. Gun working fine now, but as I said in the very beginning, the problem comes and goes. At this point, who knows. Guess the next step will be new springs if the problem persists.
