Question about Homer Ledford dulcimer finish
Instruments- discuss specific features, luthiers, instrument problems & questions
If there was a photo to see the spots you are concerned about it may be easier to give a suggestion.
That being said, however, if it's just a cosmetic rather than a functioning issue, I would lean towards letting it be and keeping it in its current condition.
If you have ever watched "the Antiques Roadshow" you can see what appraisers think of 'cosmetic restoration' done on historic pieces, which is what I think you have.

I'll probably end up getting an A4 e-ink reader like the Boox Max2 instead if the double screens music readers don't go down in price (