Gary, Which Model 3 is this gun? The cylinder photo looks like a NM#3, but has some differences. Are you sure the gun is a S&W and not a copy? Is there a ser. number on the cylinder? Ed.
The cylinder catch and lack of visible serial number on the rear of the cylinder, suggests to me that the 'TO' is an assembly mark perhaps on one of the American series revolvers. Is the 'TO' also on the frame under the stocks (grips)? Mike #283