These Ampico cork gaskets are prone to leaking.  When I rebuilt my
Ampico I used polyethylene sponge with an acrylic transfer adhesive.
Polyethylene sponge is very long lasting.  The acrylic adhesive will
not migrate and the sponge will seal very well with light spring
pressure.

All you have to do is stick the stuff on and cut the holes out with
a scalpel.  Mine was a B Ampico so I had to cut out the hole for the
ball bleed first, I think.

Spencer Chase
Garberville, California