Well, I have been around since 1949 (and bit longer) and have seen plenty of "enhanced" guns with work done long before that. The only thing I see that indicates fairly modern work is that I am virtually certain the bluing is caustic (hot tank) blue, which didn't come into common use in the U.S. until after WWII, though it was developed in the mid-1930s.
As to the gold plating, it probably is genuine. Gold plating is not expensve. Since it is so thin, very little gold is actually used, and until the Nixon administration gold cost $35 an ounce, enough to plate dozens of pistols like that.