Hello Paul,
Well, I ignored the manual,(given that it’s an 11d head and an ID block), and thought about it! The rocker shaft has two holes in the back, 180 deg apart. If the bottom hole is exactly opposite the oilway from the engine in the post at the back, and the shaft has all the output holes clear- mine didn’t- oil flows!
I put the whole lot back, apart from the rear post and washer, and turned the shaft so it lined up with the engine- ie the hole was was vertical.
Tim Walker