You guys need to outfit your survival tool box with a wider variety of generic stuff.... to wit :

One 12 X 18 roll of each of these things:

pressed asbestos

cork

paper

A tube of Red RTV gasket maker.

an exacto knife , pencil

Then when you have a gasket emergency you are prepared.. only head gaskets are not legit to do this way... although small air cooled engine ones can be made from the asbestos.

You can cut these things to match the old gasket, spread as thin a coat of the RTV on each side, let cure overnight... and you have great gaskets...