Major carbon from exhaust gasket made of cork / rubber gasket. IMHO I don't think this is a suitable material.
I picked up some high temp gasket material from Checker Auto (O'reilly's) and cut two gaskets, One for between the head and the metal air deflector on the Honda and one on the exhaust flange side. So far, so good. Not much thickness to erode out. The OEM composite asbestos one was kinda ratty.
Jimi