I got what I want. Wish I could attach the pdf shot here, but I don't know how.
What a need is a graph. With an X/Y axis. And a straight line representing the slope for 1:6, 1:7,1:8,1:9 DT bits. I use these style bits on a Router Jig/Machine called a WoodRat.
I need to set a bevel gauge to the slope line, lock it in and then transfer to adjustments on the machine. Just simple geometry. The problem arises because the WoodRat defines Dovetails by a slope rather than an angle. Rather old fashioned, I'd say.