I bought some second hand rocker towers for 10 euros a piece and I set to putting the rocker arms into position.
The replacement towers are sitting in front of the old ones in this picture - you can see that the locating holes are not oval!
When fitted to the engine I got the old problem again - the shaft was bending and I could see that the rockers were not nicely in line with the camshaft. The gaps on the replacement rocker towers were larger than with the original rocker towers:- 0.7mm above cylinder 5 and 0.6mm above cylinder 4.
There was only a gap under the towers where you can see the feeler gauges.
Looking at the position of the rocker arms and the cam you get this for cylinder 5:-
And the problem above cylinder 4 is here:-
Here you can see that when the rocker tower is located correctly over the locating ring on the head that the rockers don't line up.
Bugger!
I think the holes have been drilled slightly incorrectly in this head.
Has anybody seen this before?