I posted the same question on a Colt forum. I got a 1947 Colt Commercial that I bought thinking it was reblued. There are few things that make me think that its not. I will post pics shortly and would appreciate a feedback. One of the thongs that raise a question is that he bullet ramp is in bare metal with light machining marks just like it supposed to be. Also the color seems original.

It looks like there is some oil on it in the first picture, so a bit hard to tell. The inspector's stamp looks righteous, as to the other stampings. The little flaws seem to be on top of the blue.

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I will take a photo in better light. What do You mean by top of the blue?

He means the flaws are on the blueing, not blued over flaws.

So far I still don't know if its reblued or not. The roll marks on the right side of the slide are a little weak ( I think ) but the color looks original. The bullet ramp is exactly how its supposed to be. The only thing that comes to mind is that maybe it was restored.

I'm thinking it may be refinished. On my Colts the Flats on the slide are high polished, but the recoil spring tunnel is more of a matte finish.
Of course I could be wrong.

I think the bead blasted top of the slide (only) was standard post war till about ser# C230,000. Then they started bead blasting the underside of the slide (spring cover) and frame as well as the back surface of the slide and frame.

Hot salt blue was used (Du-Lite).
The final visual proof mark (VP in a triangle) stamped on the front left side of the trigger guard was done on the finished pistol. Look at it carefully under magnification if needed. It should show that it was stamped through the bluing finish and is not under an applied finish.

The only thing I can suspect from the pics shown is possibly a re-blue/re-polish of the slide alone.
That's just based on the light roll marks on the right side.
The lettering on that side doesn't appear even in height,,,but that was the die used at the time. You'll find that on other pistols mfg'd during that time.

Correct slide address for the ser# range. Earlier post-war commercials used up Military slides w/their billboard markings.
Production from about mid '47 / C228,000 to the mid '50's used the 'Colt's Mfg. Co. Hartford Ct USA' address.
Right side stayed the same IIRC.

The '47 Government Model kept around here is original, has light roll markings including a short "L" in "COLT" and a lightly struck Rampant Colt. Seems right side slide markings were weak on some of the production during this time.