Yep, that would probably work. After filling the perforations, a couple of good coats of primer should smooth things out, and then apply the stainless finish.
But, a few years ago, on a built, old 1/32nd scale model, I just cut off the barrels, and replaced them with thin aluminium tube from Albion Alloys, then gave the bare alloy a gloss clear coat, and they looked fine. Given the gun receivers are firmly fixed inside the wing, then the barrels can easily be cut off at the leading edge, trimmed back and / or drilled a little to give some leeway, and the tubes inserted and fixed with CA adhesive
I'll scan and post the pic of the complete weapon later this evening.