Well over 50 years ago, I had a set of badly-corroded metal valve
seats. My mentor, Mr. George Binder (who once worked at Aeolian
American), always had the troublesome corroded brass valve seats
I was young at the time and did not have the funds for nickel plating,
but tried something different. I removed the metal valve seats, wire
brushed away the corrosion, and spray painted them with Rust-Oleum,
a rust preventive paint that is still available.
I always signed my name on the inside of the chests. Recently a player
technician was working on the player, found my name, and informed me
that the valve seats are still painted and in perfect condition.