65 Barracuda tail light gasket question

Hi guys,

Is it absolutely necessary to use the hard plastic taillight gaskets that are a buffer between the body and the housing ?
Is that all they do ? Provide a buffer ?

I'm thinking there must be other ways to go, rather than almost $100 US for 2 plastic gaskets. If they ARE absolutely necessary, I'd love to know.
I'm building an old 65 as we speak.

Peter