..that I have always called an M&P. From what I have read from you guys, it would be a 1905. I don't think I have ever shared it, so I thought I would and get some info on it.
Ser.# is 152930
grips are numbered in pencil and match the gun
4" barrel
Overall for how old I think it is it's in pretty good shape. So any and all info is, as always, appreciated.
By serial number, the SCSW4 says it's ".38 Military & Police Model of 1905, 3rd Change" and as the 3rd Change ran from 146,900 to 241,703 I would say yours is a fairly early 3rd Change.
94,803 were made from 1909-1915.
This was before the heat treated cylinders, so sublime ammo is best. Looks like you have a nice one!