Many thanks for that.
Tappets are quite noisy after head gasket replacement also have a slight oil leak. Does the head need re-torquing after being run for a while?
Oil is not leaking from the rocker cover. It is definately the head gasket area. No oil water mix and very little oil being lost, though you can smell it burning against the exhaust. You can also see a smear against the block at the front and rear of the engine.
According to the receipt for the work done the head was skimmed and new bolts used. I have only just bought the car and the work was carried out by the previous owner at the end of Sept. I think I will be contacting the garage that carried out the work.