Hi Dave,
These need to wired into a switched source. They don't connect to the factory harness directly. Would be almost impossible to determine what we'd need to support. We're doing these for E, B and A body cars...
If I'm not mistaken A's didn't even have these as an option.
On the switches, makes no sense for us to try and reproduce factory switches. Yes we could, but that one isn't on our list.
As for the GM switches, here's how they look installed.
No one has ever commented they were GM to us on one of our cars...
John, how does yours interface with the car's factory wiring? Thru the original fuse block, or a power tap somewhere? I think you can find/make some better switches too....C'mon..you can do ANYTHING 
