Bear in mind that the Pre64 Winchesters have a barrel steel that has a high chrome content. It's more like stainless steel than regular barrel steel. I have an early one made in 1911. Came from my Great grandfather to my Grandfather to my dad, then to me. Someone in the past probably used steel wool to lean off a rust spot and the metal is shiny. It's a patch about 3" long near the muzzle. Over the years I've tried several versions of cold blue and in a few months to a year they've all faded away. My gunsmith is a good one and he won't even try.
Dunno if browning will work, It, like real bluing is I believe a rust process. Some Cerakote colors come quite close to looking like bluing so that might be an option.
Someone said something about the Post 64s receivers being hard to reblue. They're made of sintered metal IIRC and they first have to be plated with again IIRC, copper or maybe it was iron. It's been a few years since I bothered with such stuff. One option though; my son in law got a post 64 M94 30-30 that was speckled with rust all over the receiver. He took very fine black sandpaper and removed all the rust and blue to bare metal. A bit high maintenance but is damn good looking. Maybe a good degreasing and a coat of clear coat would work.
Paul B.