small block valve cover gasket question

[resq302]

What kind of material was used on the small block valve cover gaskets?  I am working on a 70 chally convert and the fel pro engine rebuild gasket kit that I got has what seems to be rubber valve cover gaskets.  I would like to use whatever the factory used since it is going to be a factory appearing car.  My initial thought was that they were cork originally?  Am I wrong in my thought?  Also, the tabs that stuck through were probably engine color as I would have to assume that they were on the engine prior to it being painted.

Thanks,

Brian

[maxwellwedge]

Cork - Felpro has them - not sure of the part number - I can check at home later.