Don Teach has a problem with modern leather nuts corroding player
control rods.  I wonder if treating the rods rather than the nuts
might be useful?  In an attempt to prevent the same problem where
leather-faced Aeolian valves contact their bottom valve plates,
I have tried giving each valve plate a quick spray with 3M 3900
Gloss Protective Coating.  I'll report back in 30 years with the
results.

John Phillips in Hobart, Tasmania