As above
The cam cover gasket needs to be replaced.
Sorry, this should be "gaskets" as Rixington rightly pointed out the plug ring comes separately
@ Rixington.
With martys , chances are, if the plug ring is leaking, the rest will deteriorate at some point as they maybe the original gaskets.
It's a case of, while your there replace the whole lot.
Cam cover gaskets can be reusable if they are still Supple with no cracks but it's good practice to replace them if they've been on there a few years.