CA357,

If the number you list in the original post is actually the serial number, from the butt of the gun, then it is a 1902 (2nd Model) Winchester Model from, most likely, 1904. If the number is from the yoke cut then it is an assembly number and is no help in dating the gun.

Unless someone made a replacement for the thumbpiece it isn't a "flat-latch". This style did not exist until the early 1950s on the J Frame revolvers.

Others touched on the cartridge designation, but didn't really tell you anything helpful. The caliber marking on the early Winchester Models reads .32 Winchester Ctg, and is on the left side of the barrel at this time. This was used from 1899-1914. In 1914 the cartridge designation changed to .32 W.C.F. Ctg, and this was used until 1922 when it again changed to .32-20 Ctg. for the remainder of production of the model. All three terms are completely interchangeable and designate the same cartridge.

As Muley Gil told you, all current production .32-20 ammunition is suitable for .32-20 revolvers of any vintage, assuming they are in good, safe mechanical condition.

Since the hammer and trigger are not nickeled, and if the extractor is blued, you have a virtually ironclad guarantee that the gun has not been refinished, or if it has been it was a factory job.

A 6 1/2" 1902 1st Change Winchester Model was one of my very first center-fire revolvers about 52 years ago, and I still have it. It is one I would never part with.

I have a Marlin 1894C, Colt Army Special, Colt Police Positive Special, Uberti/Cimarron Colt Single Action Army replica, Spanish counterfeit S&W, the 1902, and 3 1905 Winchester Models chambered for .32-20. I think that is all! You may get the idea I like the cartridge!

__________________
Gunsmithing since 1961