This is a rare cased S&W Model 1 First issue Fourth type 22 revolver. This is an original case with bullet block, cleaning rod and key that works. The mechanical function is very good crisp and tight. The barrel hinge is tight to the frame. It retains blue and silver in the protected areas with most of the silver on the right side of the frame. This is serial number 3749 and was made 1858-1860 with 11,671 made. I would guess it was made in 1858 or 1859 with the low number.