Hi Shroom, that bolt wasnt just missing but the machined hole and thread for it didnt exist either.
Cyl 3 didnt have oil in it as mentioned in an earlier post, but some coolant had run in from removing the head.
My plan is to repair the small cracks in the head (if possible). Ill carry on and strip out the pistons and inspect them and the crank. If all is well i'll rebuild with new shells and piston rings.
I'll also fit new oil, water pumps etc.
My eventual aim isnt to maximise engine power but to end up with something that'll be reliable for a good fews years to come, so ill be happy with refitting any parts that are within spec,.