I am not quite as good as some of these guys, but your revolver with serial number 2412xx sounds as though it is a Smith & Wesson Hand Ejector, Military & Police Model of 1905, Fourth Change.
I say that because I have two of them myself.
My older one is likely a 1917 production date and carries a 272xxx serial number. My "newer" one carries a 357xxx number and I had it identified with a Smith & Wesson factory letter by historian Roy Jinks and he dated it to 1921. I would hazard a guess that yours is a 1915 or 1916 production year.
This Fourth Change evolved in to what is commonly known as the Model 10. It's a K-frame, fixed sight .38 Special revolver.
The serial number on these can be found on the bottom of the grip frame (butt), on the breech end of the cylinder itself and on the underside of the barrel. The four digit number you noted was used internally at the factory during production and has no significance for our use.
What kind of shape is it in? Any pictures? The K-frame Smith & Wesson .38 revolver is one of
the most produced guns in history of the world. It has been suggested that some six million have been produced.
Fantastic example of American craftsmanship, but not rare.
Was it a handgun passed down in your family?