Should that number in the barrel shroud/lug match one on the frame?
It was explained to me that the number below the reg. number as an assembly number.
The serial number is above the reg. number to the left.
First, very nice RM! Second, yes, crisbee1 is correct. Lets examine the photo he provided:
I marked the photo he provided to easier explain the numbers. This photo is exactly what you should see when you open a factory original registered magnum. The red circled number, in the ejector shroud, is the serial number. The serial number here has a "B" marking to its left to denote blue finish. The "B" is not part of the actual serial number, which is found only on the butt in this era, for this model. Serial numbers should be found in the barrel shroud until the soft fitting of parts was discontinued, in the 1957 time frame. The "B" should be found there on any pre war S&W IF it shipped in blue finish, although exceptions to this rule do exist. The "N" for nickel was placed there sometime in the 1930s, based on guns I have seen. Before that, there was no letter there, which indicated nickel finish (no letter = nickel), and the "B" indicated blue finish. The "B" being found there for finish goes back to turn of the century, based on guns I have seen.
The blue boxed number is the registry number. These numbers went from 1 to about 5500. There is some disagreement on what constitutes a registered magnum IE the KC PD guns have a REG number, but were NOT shipped with registration request forms, which means they could never be registered. From what I read, this was per KC PD request, but that could be wrong.
For a few years, in the 1957 time frame, before the model numbers arrived, the serial number is found right where this registry number is. After the model numbers came out, the serial number location was moved lower, where the green circled assembly number is found. When the model numbers came out, the model number was placed here, below the serial number. At that point, assembly numbers will no longer be found where the green circle is or where the blue box is. An assembly number will still be found on the yoke arm, IE the part that actually swings out for many years.
When examining S&Ws, the rule of thumb for serial number location is
almost always on the butt (sometimes front grip strap) and
occasionally in the yoke area. Serial numbers will not be found in the yoke area of frame (blue box and green circle area) until 1957ish and later.
