Fleaflop, if you would please indulge my request. What is the number stamped on the bottom of the grip frame???

Here's my theory. The number on the bottom of the grip frame is the actual serial number of the revolver. I think what you have is a Model of 1903 2nd Change or newer. I think the barrel on your revolver is from a Model 1903 1st Change. Why the barrel was changed is anyone's guess, but that occurred with some regularity.

I went to my copy of Smith & Wesson by Neal & Jinks to see what I could find. Under the Model of 1903 2nd Change I find where the 2nd flat spring in the grip frame, the hammer return spring, was replaced with a rebound slide/spring for the hammer return.

The OP picture clearly shows the rebound slide. My picture clearly shows the absence of the rebound slide.

Thus, the revolver that started this thread MUST be a 2nd Change or newer. I am guessing the serial number on the bottom of the grip frame is higher than 51126. If I am correct, I solved the mystery. If I am wrong, then I quit and will join Hondo for a nap.

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SWCA 3297 SWHF 583