While recently reading all I can find (in promotional literature and user opinions) about cold bluing products, I've seen several indications that Winchester lever-action receivers cannot be re-blued.

There's even a guy in a U-Tube video bragging about spraying two Canadian Commemorative receivers with DuraCote. Well, that's not a look I long for...but may need to change my opinion if that's all there is (as Peggy Lee might sing).

My rifle is a 1959 vintage. On the left side of its receiver (in an area of the upper 'corner' near the hammer)
I can't tell what's going on...looks almost like khaki color. I plan to mount a nice old Williams FP sight there, and that's apt to call even more attention to the boo-boo since it won't cover it. Any suggestions?

Can my receiver be re-blued with any of the 'cold' (with application of heat, ironically) DIY products out there?
I'm thinking of trying Brownell's Oxphal (sp?), Mark Lee's Instant Blue, Birchwood-Casey's, Blue Wonder blue/ black...whichever would be the best match, since I'd like to keep this to a touch-up job rather than entire re-blue. Besides the receiver, there's a rusty/pitted section on the barrel and tube, forward of the front band.

Almost any of the cold blue products will work if you prepare the metal surface properly and degrease with a good solvent like brake cleaner first removing fingerprints and oils. I have had pretty good results re-bluing by running the prepared parts under very hot water first, degreasing a final time then applying the bluing to the hot metal. Sometimes you need to rub with 000 steel wool, and repeat the heat, degrease apply process again once or twice to get it dark blue. Make sure you keep it well oiled for a few weeks after you finish to protect the work you've done.