old school 38 S & W special. very old need some help

[S & W]

ok ive had the piece for several yeras now and jsut trying to get some more information on it. I know it is a early 5 screw. the gun has the number pattern on it at the bottom. 198 123. anyone know what this means ill post some pictures later.

[Jim Watson]

It's the serial number.
If there is no letter in front of the numbers, it is a Military & Police model of 1905, third change, made between 1909 and 1915.

If there is a V, S, or K prefix it is a much later gun and you will have to hope somebody with the right reference book reads your post.