FYI (Quality Distributor caps )

What we need are GLASS caps!! LOL

(Actually that is not true, even glass, or any other material, ceramic or plastic, can contain impurities that make the material less able to be an effective insulator/ dielectric. During WWII there were some ceramic insulators that caused trouble at RF frequencies because of the materials in the "mud" of which they were made)

I do know at one time "somebody" made clear plastic caps for some distributors