76Mintgrün, you are seriously the king of tinkering.
While we're on the subject, I'm using C.D's prescription (pretty much at sea level in coastal Australia, with 98 octane) and all is well, except for very light throttle (cruising, maintaining speed) where the engine stutters just slightly.
I suspect it might be spark related, but I was wondering what carb jet would most effect very light throttle, and which way to go to solve the issue.