several years ago a photographer named john siskin
wrote an article for view camera about building lenses and using them.
he was doing something very similar to what you are trying to do ...
you might find the view camera article helpful
http://www.siskinphoto.com/magazinearticles.html
don't forget the drain-strainer-fstop-thing instead of
the traditional iris with a single hole.
instead of diopters
you could remove lens cells from different lenses and use them.
i do that from time to time

good luck!

john