Further to my posting regarding head studs and tightening torque, I received a fitting guide for the composite head gasket together with the gasket kit (from http://www.jmgaskets-seals.co.uk) which is very informative.
Firstly they recommend tightening in three stages (40/55/65), secondly the final torque is 20% higher than the original 54. Thirdly they recommend fitting new studs.
Last autumn I fitted a composite gasket (a first for me), torqued it to 54 lbft and it soon started leaking
I have to admit I had left the old studs in place and the head had not been skimmed.
This time I take no risks; new studs ordered and head has been skimmed (6 thou). Keep your fingers crossed!
Technical advice Q&A