Thinking about your problem with the rear quarter windows: it seems odd that none of the switches or motors work, and I believe the problem is further back.
I looked at the electrical schematics for my '66, and I would think they would be much the same for the '64.
Power for all the window circuits comes from the fuse panel circuit breaker, to the safety relay-window regulator. It supplies power to the front windows, and to the master control switch. On my drawing, it looks like the purpose of the master control switch is to isolate the rear windows. When the master switch is closed, it supplies power to the rear window switches on the console and the rear seat. The fact that neither of your rear switches or windows work, I would suspect the master switch is not closing, either through corroded contacts, or a wiring malfunction. The power from the safety relay is common to the front window switches and one side of the master control switch, which explains why your front windows work, even though the master switch may have a fault.
Hope this helps!!
Cheers