Ignition dwell and adjusting it.

X2 you cannot buy a good condenser anymore.
I just changed my 48 willys to electronic this spring because of the condenser issue.
..........Probably not from automotive sources. I have not looked into a specific replacement because I'm not interested in breaker points. You SHOULD be able to determine the "typical value" of a vintage condenser and find a good quality replacement from an electronics supplier like Digikey or Mouser Electronics. You would need the right "type" to be effective and robust, heat, etc