Folkcraft plans for hourglass dulcimer ?

Hi to all

I have a few question, I got a set of plans for a hourglass dulcimer from Folkcraft, the plans were made by Scott E Antes in 1982.

My questions are.

#1 Has anyone made a dulcimer from these plans and if so how did it go?

# 2 The VSL is 27.093 inch or 688 mm, is this a common VSL? If not what is the most common VSL?

Thanks

Ron