And here we go again!

Head off AGAIN. absolutely confirmed expectation. Same problem, although I now have ANOTHER problem that the manifold has cracked.

It must have happened a while ago, as the faces of the crack are BLACK from exhaust fumes. No issue on inlet manifold, hence I suppose that's why she still seemed to run fine. Will do a repair on that for now.

Also oil in pots.. BUT reason is obvious (no other issue with the gasket this time).. Valve stem seal issue for sure, as mentioned in a previous post.

Definitely valve stem seals. Took them all out, some valves were dripping with oil!!  Hopefully the result is shown clearly in the pics. All the seals were all mashed to some degree, some worse than others. So they have all been replaced, can't believe it was as simple as lubricating them before fitting.. duh .. I feel really stupid about that. So head is ready to go back on. Just awaiting the gasket. Had the patience to take a few pics this time.