Thanks to all for the help. It is pretty clear I have a 48-3 not a 48 no dash. Other than the academics, I really do not care. It is a mint condition 50 year old revolver that shoots bug holes.
i bought my 48 no dash online a while back with matched 22 LR cylinder. Both cylinders shoot to the same point. It is fantastic. It is also pristine with box etc. The 48 no dash was made in 1959. My serial number on butt of frame and on frame in crane area has a 5K prefix. That dates it...
