Another mystery gun.
 

In a recent trade I ended up with as S&W revolver that baffles me. It is .38 S&W caliber, 5-shot, no trigger guard and the cylinder rotates clockwise. It is single action and when cocked, the trigger emerges from a sheath position from a projection below the frame.

My research to date has disclosed this may be a Smith .38 Single Action Second Model introduced in 1877 and discontinued in 1880. There are no markings anywhere on the pistol, so the mystery goes on.

Adam