Because Don hadn't fitted a gasket he had pulled the cam cover bolts down hard and damaged the end of the studs making getting the domed nuts off a right struggle! Anyway having got them off, a quick run down with a tap and die and they were as good as new. Fitted a new gasket and rubber seals and hopefully that's that leak sorted.
The sump bung was also leaking and as I didn't want to drain the oil just yet I undid it half way out, wrapped some PTFE tape round it and tightened it up. Next morning the paper I put underneath was now dry, at least it was under the sump but it showed up a water leak at the back of the head and oil from the gearbox! The head leak was the cover plate at the back of the head, it had pinholes, so fitted a new plate and gasket and that's another one done.
I treated the gearbox drain bung to the PTFE treatment and after 3 days no oil on the paper. Result!