Folks, Here is a chart that I built with my dad (thanks dad) that can be used to build any chord on a mountain dulcimer when tuned in DAD and DAC. The chart includes notes for dominant 7ths, major 7ths, major 9ths, perfect 6ths, as well as minor/major thirds, and perfect 5ths. Even though some notes are missing you can use the chart to approximate any chord. The pdf file includes a description of how to use the chart. Hope this is useful to others.