What strikes me is how very far apart the strings are on such a wide fretboard. The fretboard is clearly intended for chording, but wow that's a wiiiide space between strings. Gotta have man-hands I guess. 

That soundhole looks like a primo place to lose your pick in!  But the pick would come right back out easily.

Hi Nate and thanks!

I've seen hundreds of dulcimers beyond the few hundred I photographed, and this dulcimer and its design is absolutely unique. I'm not a builder, so I don't know or have a feeling for whether not continuing the fingerboard piece through to the end is problematic or not. It makes for a huge 'strum hollow,' doesn't it? 

There were some older dulcimers and zithers that had holes in the (hollowed out) fingerboards themselves, but I can't recall, nor have a picture of, any hearts being used there. This would still be different from that. It's certainly the largest heart I've ever seen on any dulcimer!

I also don't know if Mr. Abbott made more dulcimers like this or not. As I did most of these photos on the fly - eg, before or after a workshop - my record taking was uneven. It was a small miracle that I found the pages of some notes after a few decades, and I'm not sure in most cases exactly where the pictures were taken. In some cases I didn't get the name of the builder.

As I post more pictures, I hope I might actually hear from some of the folks in them and manage to get a few more details in cases where they are missing. 

Something about taking the very traditional heart shape and giving it to the very nontraditional placement of a guitar soundhole is very aesthetically pleasing to me! Super cool thank you very much for sharing these pics!