Pushbuttons suddenly inop!

I agree that the pushbutton units are durable. I have a few that I've collected for the day when one actually does fail, but I don't think this is a control unit failure.
Having partially disassembled the control units I have to clean and lubricate them, and looking at the one on my bench just now, I'm just not seeing what in the control unit could fail and prevent any of the buttons being pressed. The shift cable or the "rooster comb" that actually perform the gear selection seem more likely.
Of course, as always, I might be wrong. In any case I will share my findings in hopes of helping anyone else who has the same king of failure.

The 64ragtop is not my daily driver and other "stuff" has kept me from actually dropping the pan to inspect the transmission end of the linkage, which is why I've been hoping for someone who has had a similar failure to chime in with THE answer. No such luck as yet!

With any luck at all, I'll clear the decks and get to the issue at hand in a day or so.

BC