grand dad's biggest old hit & miss engine's head gasket had been blown since i was born. got tired of it one day afew years ago. sanded both the head & block down with 80 grit. sprayed 3M 77 on an aluminum level to hold the paper. used the level because it was the only thing laying around that had milled sides that were guaranteed to be flat to some degree of accuracy (not high)
traced a new gasket out of a (grossly overpriced) roll of copper from hobbylobby.
ringed it with a nickel-steel E string off a guitar by taping it to the block, installing the head & beating the shit out of it with a block of wood & 6# sledge to seat the wire.
didn't have copper kote, but used an old can of whatever GM's version of copper kote is
it gets run maybe 2-10 a year to pump water out of a spring/rain filled well when its filling too high or cut up trees, but its run without leaking since.
can't really see it in this picture, it had changed color by then and the engine is old green paint so it kinda camos it.