I do believe the real title for this revolver is, S&W 32 DA #4 as in the 4th make of that series. I did open it up again, and after carefully studying the working of the gun, I spotted a small burr on the bottom of the hammer. Pulled the hammer and sure enough that was supposed to be the single action sear notch. At some time the bottom of the hammer had been radius-ed with a file almost removing the notch. I found the schematics for this handgun on Numrick arms site, the hammer shown looks like mine but has a definite sear notch on it. The hammer is out of stock right now, so I will have to hunt down my needle files and try to re cut the notch. I guess I have nothing to loose on this hammer the damage has been done. The gun shoots very well in double action mode. Oh after thought Numrick does have a barrel and cylinder in stock, I just may order them and redo the nickle plating on his gun. The original barrel has lost a lot of rifling over the years.