Oil leak on the timing advance

[Jugostran]

Hey all!
I am just getting started with overhauling the engine of my BX, and a thing that has been bothering me is this oil leak. I think it is coming from under the starter actuator, but I could be wrong. (indeed I was, check PS)
Me and another chap who are working on the car don't have a clue on how to fix it, so any suggestions would be greatly appreciated!


Notice how the yellow vacuum line is coated with oil. I suspect the insides of the advance are also gummed up.
EDIT:
Also, ignore the fact that there is oil on the advance itself. This is from the fuel pump which started leaking recently.
PS;
I have since learned that this isn't a "started actuator", but is instead the timing advance on the distributor.

[Jaba]

Its not clear to me what the starter actuator is. It looks to me like the timing advance on the distributor. If I am correct then the leak will be coming from the distributor, either from the base where it is held in the cylinder head which is sealed with an o-ring or the distributor can also leak via its central shaft, a new dizzie is the easiest way to fix that.

[Jugostran]

Its not clear to me what the starter actuator is. It looks to me like the timing advance on the distributor. If I am correct then the leak will be coming from the distributor, either from the base where it is held in the cylinder head which is sealed with an o-ring or the distributor can also leak via its central shaft, a new dizzie is the easiest way to fix that.

Ahhh, so that's the distributor. I'll get that O ring changed out and the distributor replaced.
Just one question. What size O ring do I use?
Many thanks for the answer!

[Jugostran]

Its not clear to me what the starter actuator is. It looks to me like the timing advance on the distributor. If I am correct then the leak will be coming from the distributor, either from the base where it is held in the cylinder head which is sealed with an o-ring or the distributor can also leak via its central shaft, a new dizzie is the easiest way to fix that.

I did a bit of work in the area around the distributor.
I cleaned the contacts on the timing advance and changed the thermal interface stuff that was there from factory.
Trouble is, I am a bit afraid to touch anything related to the distributor because I don't want to mess up the timing.
What should I look out for before I remove it? I want to give it a once over and determine whether I can repair it or do I need to replace it.