Doug,Nice work!
Earlier cars had a key to lock the wheel on and two "mushrooms" to release the wheel. Later units have no key and two flanged stems to release.Markus
Your snap- off hub looks a little different than the one Fredrik P posted above.
Yours has some sort of key?
I agree. I need an adapter plate. Unfortunately, I'm no machinist.
Doug
Yep, that is the one.