Wash the ceramic element you have in vinegar.

Gaskets can be made from a variety of materials. We generally use cork for the fuel filter gaskets due to the thickness required. Very difficult to cut the desired thickness in some of the other materials.

As to elements; Carter produced many different ceramic elements, all that are very close in size. Trying to get the correct one is difficult. Too small an element will not seal. Too large an element will crack the bowl.

Jon.

Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify.
If you truly believe "one size fits all," try walking a mile in your spouse's shoes!
The Carburetor Shop