Cold blue will set you back no more than 10-15 bucks and some time. Results vary wildly and depend heavily on how you go about it. Degrease thoroughly before applying the bluing, warm the metal up a bit, apply the bluing, buff with XXXX steel wool, re-apply -- many, many times. Eventually you may get something you'll like. Note that some manufacturers say their product requires no degreasing -- but don't believe them!

But you know, bare metal isn't all that bad. Keep it well-oiled, of course, and eventually over time it will develop a darker patina that to some eyes (like mine) can get to looking rather pretty. I have an old Rossi .38 that was terribly rusty when I got it (real cheap -- $65, if I recall correctly), so I just stripped the rust and remaining finish and kept it oiled. I has done a couple of decades now as a tackle-box/backpack gun and has not developed a speck of rust.

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Pisgah