I'm not sure if this is but so helpful, because this is vastly smaller in size than what you're asking, but I have fallen in love with my 17" Feather Dulcimer. I loved playing my Walnut Creek, too, but there were songs I never could get that I seem to just play out of the blue now. That makes me think a 26.5" (and I see you added 25") might be beneficial to some.
Thanks hugssandi and others- your comments are indeed helpful. I decided to use a 25" fret board pattern for my April dulcimer
updated by @bob: 04/12/17 12:19:40PM