My GI 1911 was manufactured in 1913. It left official government service at the end of WWI. It went to WWII and Korea before I purchased it in 1976 from the grandson of the WWI vet. It has not been refinished. It takes hard use and I have not had a rust problem.
In the case of form follows function, I think a parkerized finish is a very becoming way to dress any fine firearm which is to be used and not set in a display case.