I hate to show my ignorance, but what are coke grips?Factory Nickel 5 screw pre-29 will have a "N" stamped on the side of grip frame and the rear cylinder face. Serial # should be in the range of S130000 to S167500 but could be as high as S174599. Four screw pre-29s range from S167500 to S184000. Not worth a five screw but still a high dollar revolver. Heck a good set of coke bottle grips can bring $500.