I agree it is a pre model 10, pre-Victory model M&P
The serial number & caliber is for a WWII era gun, and it has been chrome or nickle plated, probably recently.
The way you can tell it is not original is, they didn't make any of those in chrome or nickle back then.
And they never ever plated the hammer & trigger like the one in the photo. The gun would have been a dull blue-green similiar to Parkerizing, and the hammer & trigger would have been color case-hardened when it was made.
The reason the markings appear worn & hard to read is because the plating shop buffed them off with a buffing wheel before plating it.
I would proceed with caution if you are thinking of buying it.
.38 S&W (Not .38 Special) ammo prices will shock you and it will be hard to find.
And mechanical reliability of the gun may have been compromised by the bumper plater who buffed & plated the internal parts.
rc