Thanks for sharing those photos. I would say that the string spacing on that dulcimer is pretty unusual, which might make it extra difficult to play. If you look at the dulcimer in the 4th photo you attached, you can see that the two melody strings are usually close together, and the "course" of paired melody strings is equally spaced with the other two strings. I'm not sure if your father in law intended for it to be "paired melody strings" or "four string equidistant" but I think it would difficult to play in either.
Also, there are many different ways to hold a noter based on your preference, and I recommend joining the "Old Style Drone & Noter players group if you haven't already.
https://fotmd.com/strumelia/group/19/old-style-drone-noter-players
updated by @nate: 11/26/24 06:27:20PM