All E-Types leak gear or engine oil - Fact or Fiction?

After years of experimentation I've found that all engine leaks can be sealed except two places. The half moon cork seal at the rear of the sump is very difficult to seal completely.

Also the standard cam cover paper gaskets are too thin. If the cam cover bolts have ever been over tightened in an attempt to stop leaks, the covers will not be flat. I've tried sanding on a surface plate but they still leak. I've tired gasket sealers (permatex, silicone, etc.) but they all seam to soften and leak oil, and then cleaning them off is no fun.

Engel Imports sells Metalastic cam cover gaskets (thin layer of aluminum covered with silicone). I recently purchased a set but have not yet installed. In theory these should solve the problem as they are thicker and more compressible than paper, and will not wick oil. Metalastic should make a more effective sump gasket as well if anyone makes them.