Just what the title asks.

"Elephant snot"(3M trim adhesive)the gasket to your cover and then use grease(thin film) between the cover & head.No more issues.

I think the FelPro is a cork/rubber composition.

And what Z train said- I've had my cover off numerous times without leakage.

You mean no one makes the heavy rubber reusable gaskets? That explains why I can't find one.