Thanks Jai, I think it probably needs the valves out looking at it but was hoping to get it skimmed and then do the valves one by one so I can be sure they go back in the same place!
Get 8 pots labelled E1 to 4 and I 1 to 4 and you cannot go wrong. You will still need to relap the valves in, and or have seats recut if changing the valves/guides on inspection.