The serial number is 65754, which I believe is in the right range for the 1906 commercial.
The tip of the pin is not blued, so it has obviously been installed before the bluing. The slots behind the knobs and the recess for the coupling link are in the white, which I believe is the case on all factory rust blued guns. I just disassembled it, and it appears to be finished just like the factory did, with some of the inside being in the white.
I can't really see a halo around the numbers on the barrel, maybe a little bit of frosting but very little. The ridges around the numbers are still there, so it has not been polished. The rest of the stamps are also nice and crisp, and there are none of the roundovers you will normally find on a reblued gun.
If this is a reblue, it has been very professionally done, to the point where you would think that it's a factory job. The inside of the frame has very sharp lines between blued and white areas, exactly like what you would find on a factory blued gun. I don't know if they ever reworked any commercial models though. From what I gather, they did rework some parts and guns at the time of model changes, just to be able to recycle what they had in inventory. I can't really see why they would have done that on this one though.
So I guess the question now is if this could be a factory rework of some kind. The finish has clearly got a lot of age on it, so I'm sure it's not a modern day restoration or a fake. I mean, if anybody had the knowledge and patience to finish everything to factory specs, why leave a stupid pin out? And looking at how crisp the gun is, why would it have needed a refinish in the first place?
