Brian
Have you seen my posts and videos using the EX3/Nano/Red Rock Encore?
If you are using the EX cameras then the new Encore with the new achromat (designed specifically for the Fujinon stock lens) from Red Rock Micro is a extremely solid solution and I really love this new tool. I too use the Nikon lenses and would love to own the Zeiss prime.
http://kateearl.com/
I borrowed an auto focus lens from a friend and I needed to push a pin and close the iris down before mounting the lens, I was only able to open the iris while it was mounted but you it work, however I would recommend manual lenses.
Good Luck
Michael Palmer