Beautiful WWll 1911.
I have a Remington Rand with serial number 1589xxx that's in similar condition. I haven't heard the darker serial number item before for an original finish gun. The serial number on mine looks identical to yours in condition and on close inspection, the ordnance stamp does appear slightly "shiny". I paid $850 for mine in '99, from a dealer here in KY...not a steal by any means but considering its condition, I bought it.
All of that said, I don't see any dings or other signs of extended usage on yours. If these are present but appear to be filled clear to the bottom with parkerizing, you can assume a refinish has been done. I don't see any dings on your pistol whatsoever. I do agree that the white highlight was done by a previous owner (your Dad possibly) and is easily removable, if wanted. The minimal wear on the barrel chamber, trigger and no wear visible on the grip safety indicate to me that it seen minimal usage.
I'm a shooter, not a collector and mine gets a range day from time to time. It's got tight lockup and a fine HS bbl. that will confidently put all 7 into 2" @ 25 yds, with 200 gr. target grade LSWC's from a solid rest. Too, I especially like the shorter trigger on mine...it just fits me better than the longer ones. While some may complain that the sights are too small when compared with modern 1911's, I find them entirely useful for the gun's intended use, and don't hang up on a holster when drawing. High target sights were not needed in the slit trenches and bunkers of my misspent youth in Vietnam.
Best of luck with yours, and DON'T EVER SELL IT! I'd be interested in range results if and when you shoot it.
Rod