I've got the original covers. Far as I can tell I've got the flange flattened out pretty nice so they should seal, but couldn't get it done with the cork .... could be I'm afraid to tighten them enough because I don't want to bend the holes again. Now that the engine is all buttoned up and tested ... I could try cork with some washers under the bolts to spread the load a bit .... come to think of it I'll have to check and see if I'm using the proper flanged OEM style bolts.
I once did up drawings for a "load spreader" that was about 1/2" thick and went the entire length of the lower valve cover from bolt to bolt
