Then and Now Automotive will sell real cork ones to you. I have rubber on the Cadillacs and cork on the AD. The cork seals up a lot easier than the rubber.
Just a note that it isn't a sediment bowl but rather just a glass cover (as referred to by GM). It does not catch or trap sediment due to the nature of the design. The fuel creates too much turbulence as it flows through for any solids to remain trapped in the bowl. All solids get trapped in the fiber element.
Mine seems to work as a sediment bowl, looks pretty original to the 283, 2 bbl Rochester. It is an AC brand and I use the paper filter/spring and it does collect some fine sediment.
