The question seems to be "Can a blued gun be re-finished in Stainless?", is that right? If that is the question the answer is NO.
Stainless steel guns do not have a finish applied to look that way, they are made from solid stainless steel and the "finish" on them is merely in how the factory did the final polish. They can be polished bright, brushed or glass beaded for a matte appearance, but other than that, and the final treatment known as passivation, there is no applied finish.
Blued guns are made of various "carbon" steels that are, depending on time period or manufacturer, blued by a variety of chemical precesses to achieve the dark color which is nothing more than a very refined rust coating on the metal.