<VV> Exhaust Donuts

[Bill H.]

                                                                                 B"H
Hi all...as cooler weather arrives, I now have to replace the lower shrouds on my Monza as well as replace the 4" heater hoses so I have heat for the winter.
While the shrouds are still off, I thought it might be a good time to replace the 6 exhaust manifold donuts as well to ensure the heater is as safe as possible.  I ordered new ones from Clarks; they are of graphite but the surfaces are scratched and not perfectly smooth.  I am wondering whether they should be lightly sanded or smoothed out?  Also, can I apply some Permatex Ultra Copper to the flanges on both sides (manifold and stacks) to ensure a good seal?
Thanks for your advice on the subject in advance!...Bill Hershkowitz 66 Monza Sport Sedan 110 PG A/C