Background: I'm the 2nd owner, have had the car for over 20 years, it had 67k on it when I bought it, so I believe this is likely the first time the Autolite 4100 has been off the car. But if this is not an original factory 4100 gasket that would be interesting to know. I took lots of good pics before removing it and prior to disassembly if any one needs pics of an original 65GT San Jose built car.
So the carburetor base gasket and spacer gasket look like this?
They have a metallic core throughout and the exposed metal areas seen in the pic. It is metal, tested it with a magnet. Nothing like what you can get in the parts stores now.