Fretboard widths and wood chocies
Instruments- discuss specific features, luthiers, instrument problems & questions
Just a quick comment here that fretboard width and string spacing are two different things. My personal preference is for the strings to be no further than 1 inch from bass to melody (on a 3-string instrument), but I still like a 1-1/2" fretboard since that provides more room for bending strings.
Cherry and butternut sounds like a nice choice. I think I agree with others who suggest that wood choice has much less of an effect on sound than many other aspects of building. I usually choose wood based on looks and the builder based on sound.

To Rod... and our other Absent Friends.
It sounds Celtic to me, too, but Ken may be right that there are pieces of a couple of tunes there. Part of it is a melody I know, and I may pop in in the middle of the night when I remember it's name. But I don't recognize that descending ending/turnaround.