I will have this project done in a few days. I purchased a standard Greenfield kickstand and will use some aluminium stock that will have two grooves machined in it and sit straight down under the seat. one plate on top and another thicker piece underneath. Each with one hole in them. A bolt will run down thru the top plate, thru the bottom plate and into the kickstand underneath. When I tighten the bolt it will clamp down the plates and kickstand and that should do it.
I will make a few extras if it works as there seems to be others looking for something that will work.
Kenal0