These are guys rebuilding them for insane money because they restore them to Hemi Charger standards.
One or two NOS out there. Hold your breath.
Used ones that are working are very expensive but may go next week.
I bought a gear replacement kit years ago that I keep on the shelf. Haven't seen any around lately.
The more you Google looking for one, the closer you may get to finding one.
After you turn them on to go up and they don't...gently tap on the side of the motor with a hammer and see if they open. My "79 New Yorker does that some time and I suspect I heard the solution listed above. If I remember the cost to rebuild one is $400+.