During the two world wars there were a number of companies that made 1911's for the military. Ithaca was one of them in WWII. Most of the pistols produced were sent to England, with many returning after the war. they are not a rarity, but may command a grand in mint condition. If it has be plated with anything, it has basically losts it value for a collector and the price should be three hundred, or so. The other consideration is what the other parts are from. The small parts do not hurt the value, unless they are poor replacement parts.
I would say that unless you are getting it for very little, I would leave it alone.
dclark