For a good deal of time I had assumed that I'd need to sand it back, so never bothered dealing with the problem.
More recently I'd been reading up on furniture finishes as I am working on a few things for the house.
One finish piqued my interest was French Polish. One reason was that its old fashioned and another was that its fairly easy to repair with a bit of rubbing & alcohol.
I wondered whether it would be any good for fixing my guitar.
Since it wasn't in the best of condition I figured that I couldn't make it much worse.
Actually I had bet on it doing nothing at all.
Turns out my intuition was wrong.
I have pressurised isopropyl alcohol for cleaning circuit boards, so I sprayed a bit and started rubbing it in with my index finger.
Almost immediately it began to to change the finish.