New Gas Can Gaskets?

I have several metal gas cans. Have the reversible
spout/lid.
Over the decades, all the cork gaskets have shrunken
to the point they don't seal or disintegrated completely.
Not finding any replacements, I bought some cork gasket
material and cut some new ones. They fell apart in
a month.

Anything I can use to cut new gaskets?
Needs to be something that costs less than new gas cans
and that I can buy without a $50 minimum order.

Google gets a zillion hits, but no conclusions.
Several of the gas resistant materials are NOT
alcohol resistant. And it's almost impossible to
buy gasoline that doesn't contain alcohol.
No, I'm not driving out to the airport.

Suggestions?
Thanks, mike

 

Nor am I.

 

Neoprene rectangular cross section 'O' rings?. Butyl rectangular cross
section?. I use a K&P oil filter which is sealed with a Butyl quad ring. Try
your local bearing/seal supplier. They can be a mine(field) of useful info.