I see many photos here of great metal work while the gun is still in the white. I imagine some of these projects are completed over months or years of time.

What do you use to keep rust at bay while working on metal in the white?

We don't have much problem with rust in this area. We're a pretty dry climate here in Utah. But if I were worried about long term protection for "in the white" projects, I would want to wipe off all finger prints with a lightly oiled rag between sessions.

Rust from dampness is an issue here in Michigan. I spray bare metal with WD-40 if it is going to be idle for a few weeks. If a long time is anticipated, I wipe down with motor oil.

Same here (Michigan) I never had too much of a problen since I use a lot of oil when I do machine work. I just don't clean it off when I'm done. Mostly laziness, but no rust is a good side effect.
Don