Wow, this is an amazing thread!
I was taking a closer look at my grandfather's .38 S&W. I thought it was a M-10, but it appears to be much older. I think it's a .38 spl M&P 1905 with four screws on the sideplate and one where the trigger guard meets the frame. It has a square butt, wood checkered grips (they cover one screw) with a small, flush brass medallion near the top of the grips. The finish is nickel and the barrel is 5". The front sight is a half moon, but they all appear that way as far as I know. The serial number starts with 253.
An approx. year of manufacture would be much appreciated. I'd never sell it. I'm just curious. My grandfather lived though the Depression and was a constable and a coal miner in Ky.
Thanks for any help,
Don