Quark?
Don't think I have heard that term since college physics
Somehow, there must be another meaning; I cannot really associate sub-atomic particles with a stovebolt 6.
All joking aside: Vetteman, the originals were sometimes bakelite, sometimes a fiber compound, and aftermarket versions were often make by cheaply laminating (read as fastening together with long staples!) a number of asbestos flange gaskets to the required thickness. Often, enthusiasts machine them out of a block of hardwood, and just as often paint the edges black.
Jon.
