How to restore old dulcimer?
Instruments- discuss specific features, luthiers, instrument problems & questions
Well, bill, I don't know from A C D D# ... but if you tune the melody string to A, and don't get a reasonably clean do, re, mi, fa, sol, la, ti, do scale when fretting up from the 3rd fret to 10th fret, there's not much you can do except wall hang it as a unique piece of folk art. I'd hate to mess up that nice carving on the fretboard by taking out frets and re-setting them at different locations.
"...don't know what to do with the scale..." Huh? If it sounds good, you play it -- after you lower the action about a foot and a half
. All that will take is some serious sanding and re-cutting of string notches. Nothing wrong with a 24"-25" VSL. You can still tune it DAA, but you'll want to check a string gauge chart to make sure your've got appropriate gauges.

I attached some photos.
The tin or penny whistle was an instrument I tried to play once upon a time and had trouble getting the right notes on it too. And there is the added disadvantage in that I couldn't sing while playing it. So I could never remember the tune I wanted to play.