OK, those recently posted photos show a refinished lacquer that's deteriorated. It remains shiny where it's still in place, and the bare brass where the lacquer's come off has turned brown.
Extremely ordinary condition.
If you'd like to reduce the contract between the brown bare brass and the shiny lacquered brass, you could have a go with Simichrome on the bare brass areas to see if it will lighten them a bit.
I would NOT get into stripping finish on a horn in this condition. The finish that's still in place down under all the mechanism (and it mostly is) is protecting the brass from corrosion. Strip that off and the whole horn will become a big verdigris factory, primarily down under the mechanism where it's very difficult to clean off.
Extremely ordinary condition.
If you'd like to reduce the contract between the brown bare brass and the shiny lacquered brass, you could have a go with Simichrome on the bare brass areas to see if it will lighten them a bit.
I would NOT get into stripping finish on a horn in this condition. The finish that's still in place down under all the mechanism (and it mostly is) is protecting the brass from corrosion. Strip that off and the whole horn will become a big verdigris factory, primarily down under the mechanism where it's very difficult to clean off.
