It was probably from late 1953 or 1954/1955. I have a pre-Model 30 .32 Hand Ejector, Modified "I" frame, 5 screw with round sight that lettered to December 1952, serial No.5957XX. It does not have the flat latch or the "ramped" sight that yours possibly does so it is right before the mods. Does yours have the small round trigger guard or the elongated one? Is yours an "I" frame or a "J" frame? Hope this helps locate the date of your gun. T44