Carter pans are subtle things. Especially when they get older. Because who doesn't recognize that eternal drop at the carterplug? Who has never experienced that the plug, when it was last checked, stripped its thread so that the freshly changed oil entered your sleeve?
The solution is simple as always. With a Brezan presentation we saw the Smart-O plug. A crankcase plug with an O-ring in the threaded part. If that O-ring has even a thread in the oil pan, then the case is leakproof and secured. Finger-tight tightening is sufficient.
The Smart-O plugs are sold via Brezan in assortment boxes for a euro or 200. So that is for garage owners who cover around 95% of all sizes with that range. But as classic enthusiasts, we are naturally smart enough to flood Brezan with requests for individual purchases. They will probably find something on that.