Re: Colt 1908 Vest Pocket .25 ACP
FWIW, I don't think it is nickel plating, I think it is chrome, which the factory never offered. Further, as noted by others, the gun was rusted, then the rust buffed off and the gun plated.
Look at the second and third pictures under #11, and you can see the pitting on the frame that was plated over. Also look at the grip safety in the third picture; there are rough areas from the rust that was cleaned off. That part, as well as the safety, should be color case hardened.
I can't comment on the pearl grips without seeing them; there are several kinds of synthetic grips that can pass for mother of pearl in a picture.
My valuation is around $200, but if the grips are MOP, then add $100.