So here the result
I used my pressure gauge for the first time. So from the intake vacuum line the pressure was around 18/19. So that, from what I read in other posts sounds good. I plugged this vacuum line, but left the advance vaccuum line connected with the carb one.
By the way, should I have tested the pressure coming out of the carb vacuum line also?
Anyway. With this set-up the car really did not drive "well" at all.
I then disconnected the advance connection to the carb vacuum line. Plugged the line coming out of carb. But left the line going into the advance open. The car drove reasonably well again.
What does that mean in your opinion., Should I change the vacuum advance? I actually looked around, does a vacuum advance really have to cost over 100$. Is there a cheaper option somewhere to be found?