It has a simple pinned lap joint holding some scrap Cherry legs together. In use, raise the pin board just higher than the vise jaws with a thin piece of scrap. Use the same piece of scrap to hold the tail board at the correct height, square the tail board with the dovetail marking square and mark out your pins. A piece of cake or as my foreign clients would say "a sheet of cake".
This morning I made a quick and dirty set of dovetails to test the appliance out. It is a winner, the base alignment was perfect. I could not feel the slightest difference between the boards. Now the question is....Why didn't I think of it first?