Geoffrey R. Johnson Dulcimer?
Instruments- discuss specific features, luthiers, instrument problems & questions
I have not heard of Mr Johnson, but I would go by the VSL (distance between the inside of nut and inside of bridge) to make a determination, at least to start out, anyway. My dulcimers usually have long VSLs (27"- 28"), and I use .012" plain steel for the first and second strings, and .022" wound for the drone. Nice looking dulcimer.