I think the difficulty of using sandalwood might be in finding a useable piece to work from as it is not a big tree and it grows kind of skinny. It’s also very expensive stuff, at least the grade used for cosmetics and perfumes is. It’s a valuable export crop grown in very small amounts in Australia. I was wondering at using the kind of approach to building a melodica body as a guitar or ukulele, so solid top or body, or laminate? What kind of wood, Spuce, hoop pine etc? My guess would be that any of the woods used to build good ukuleles would be good to provide that warmth and volume. Koa, monkeypod, mangrove, maple, agathis (like mahogany), mahogany etc etc. Solid wood sounds ‘better’ but is harder to work with and more sensitive to chnages in humidity. Laminate gets a bad rap but is actually a more resilient approach that is tougher, lighter and not that far off solid wood in sound. consider the early Japanese Martin guitar copies that were made in laminated wood, beautiful sound and as highly sought after as other solid body guitars these days.