Since it is brass, I bet the same acid bath mix or the Us cleaner mix band repair techs use on a trumpet or tuba would get that bright as new. (It is nasty what comes out of a neglected instrument,) As the core is hidden in the dash, empty of electrolysis and whatever deposits is good enough. I hope it still holds pressure.
This place has US cleaners and different cleaning fluids. You might find one with rust inhibitors you like for other metal projects.
This place has US cleaners and different cleaning fluids. You might find one with rust inhibitors you like for other metal projects.
After. While it cleaned up, not sure I’d call it good as new
Biggest difference was internall....soo much gunk came out after the sonic baths