Looks like you got a nice shooter.
Yes I agree with Wiregrassguy, it may have been reworked,repaired, or refinished at the factory at some point. But it's been refinished since and not by the factory; wrong glossiness and inferior pre-metal preparation. We need the date to possibly tell more. A photo of the left side of the grip frame with grip removed could be more helpful by showing additional factory stampings.
The grips are not factory nor presentation, just common after market grips.
There is other serial #s, including on the yoke but in the location described below:
SERIAL # LOCATIONS: To confirm all parts are original, one can check for the 6 (or 7 - Triple Lock models only) matching serial # locations for fixed sight pre war Hand Ejectors and all post war Hand Ejectors thru ~1956 and a few as much as 3 years later.
NOTE: Observing serial #s with accuracy or even existence, especially on penciled stocks, requires magnification, bright light, and an attitude that they are there!
1. Grip frame butt (prefixed by a letter(s) following WWII) - or fore strap on I frame Regulation Police models and single shots with grips that cover the butt
2. Barrel - bottom of barrel or in extractor shroud, (Triple locks have tiny #s stamped in front end of the shroud; sideways/vertical if over 3 numerical digits, otherwise horizontal).
3. Yoke - on rear face only visible thru a chamber with a flashlight (except the .32 Model 1896 and no doubt a few others)
4. Extractor star – backside (which is actually the side facing the muzzle).
5. Cylinder - rear face
6. Right stock only - on back, scratched or penciled depending on vintage and stock material, stamped after 1929, (except most post war target grips because individual fitting not required.)
7. .44 TL models only: rear side of middle lock cam plate (Triple Lock models only)
Pre war serial #s on the butt read with barrel to the right and are centered, or offset if produced with a lanyard swivel (factory installed swivels are drilled with a jig and always 1/10" forward of center). Post war #s read with barrel to the left and are all offset to the rear.
Also look for a diamond or other stamps following serial # locations, they can tell us more.