For anyone interested these are available in kit form from https://westoakstudios.com/contact-westoak-studios/. I believe he is getting the rubber dome assembly from the originator and cutting out plywood parts on his cnc.
I contacted Michael Samarza there about getting a wingnut replacement for the original slip-nut on mine and he sent one at no charge - a nice guy! Thanks to Joe Calhoon for the hookup.
This is an incredibly useful tool for working with sheet goods or heavy lumber. https://www.youtube.com/watch?v=Pzg7ZZ57ydc