Skim the cilinder head or not?

[MKoers]

It's a bit off topic but I think the answers will come in handy.

My mother drives a Opel Corsa 1.4L 8v.
Now I serviced it this week and noticed it poores out oil underneath the cilinder head.

Compression is OK but I can see oil comming out.

So I'm gonna place a new headgasket.
As the engine never ran to hot: Do I have to skim the head or can I just bolt it on with the new gasket?

 

[trackdayqueen]

Take it to be skimmed, they can check whether it need it or not. Might as well if the head is off.

It's 'cylinder' btw!