312 Intercepter Crankcase vent gasket

I have the intake manifold off my 312 Interceptor to rebuild the Carter YF carbs and have discovered the source of a long term oil leak at the top of the engine.

The gasket shown in the picture is for the crankcase vent that is under the rear carb air intake bell. It was badly misaligned and letting oil go right by it into the valley pan. The gasket as shown is possibly serviceable, but it doesn't seem to have any elasticity left, and it doesn't seem that it could ever actually seal the joint.

I have been looking all over the internet for a replacement gasket set, but so far have turned up nothing. Also spent several hours reading all the Interceptor posts here on CCF and didn't turn up anything - sorry if this has already been addressed.

Are there replacements available or do I need to get gasket material and cut a new one?

If I need to get gasket material, what type will work best? The two gaskets I have (front and rear) are both intact but hard as a rock and I cannot tell how spongy they should be.

- Gary