Water-contaminated oil can be seen lying on top of the head.
The top pair of studs have been replaced with over-length items: hence the two brass spacers. Maybe these will be put back to standard during the rebuild.
Exhaust manifold removed to reveal that the hot-spot gasket had also burned out on its upper edge - see the carbon stains on the inlet manifold.
Manifolds off and a good view of the two repaired (and now failed) tappet chests.
The single,lower hole is the tract through which the fuel mixture is drawn from the carburetor mounted on the other side of the head.
Extreme right is the clamp ring that alters the magneto timing. Actuation works its way from the steering wheel, down the stator tubes, through the steering box, up the right side of the engine then around the back to what you see here. So simple, I wonder why nobody else thought of it!
One method to remove jammed studs: lock two nuts together on the thread and unwind the inner one.