Kind of hard to believe. 64-72 is a lot of columns. Seems like a steady supply would be available. List the vendors you tried so I don't repeat. Is the bearing I linked correct? Is it part of the turn signal plastic housing? The bearing may sometimes be referred to as a "mast bearing". But they are usually the ones with the integral horn wire.(different application)
You may have to buy this to get bearing. Not sure if this is what you have.
https://www.tuckersparts.com/Turn-Signal-Switch-CTS-6466.html
