A comp test showed better figures than before - 190 - 200 psi in all three pots, flippin' zero in #3. Rocker off, rocker shaft off and found this

Undid exhaust, inlet manifolds three bolts (to find no gasket, just red silastic

leaving manifold insitu (sorry Greg ! T ) head came off so easy compared to belt driven camshafts

Found no damage to the valve or piston.
Suspected that the first few attempts to push 8.5 year old fuel through may have been the cause to gum up one inlet valve in the partially open position.
I drained the crap from the crusty old fuel tank and put fresh in before I got beast running, so must have been tiny amount or new fuel dissolved crap from tank walls and fed it through.
Now waiting on a special parcel from our Grayland member * cough, cough with some head gaskets
Head is soaking in prepsol and gonna get a valve slippin' again I hope !