Here is an I frame my nephew picked up recently that seems somewhat interesting. It's a Square butted, snub nose 38 S&W revolver. It's in, as you can tell, pretty rough shape, but what is interesting is that, according to the Standard Catalogue of Smith & Wesson, the factory made two models, the Regulation Police- which was a square butt four inch barrel, and the Terrier-which is a round butt, two inch barrel. According to the SCSW, there were some square butt, two inch barrel Post Office marked Regulation Police models made, but this one doesn't have the markings. The SCSW also states that the authors had seen a model like this, but were not sure what to call it. All of the serial numbers, including the barrel and the grips, match. He is planning to get it lettered ASAP. Probably not anything super valuable due to the condition, but he's not going to sell it anyway. It is a nice piece that you won't see everywhere, although, they say you could order almost anything from S&W in those days. This is my first attempt at posting pics, so bear with me.
roosterk

Assuming the barrel hasn't been cut or swapped the possibility of a limited run or special order always exists.

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No life story has happy end.

I can't help with any specific info on this particular piece but can tell you that there are several unintentional errors published in the Standard Catalog. And most stem from around this era ( early post war).
Hopefully Roy's letter will be able to shine a little light on this piece.
Any way you go this is very interesting piece and a neat find.
Please advise when you get the letter and tell us the "Rest of the Story".
Thom Braxton
SWCA #1474