if you change the head gasket, then make sure the liner height s are within tolerance - otherwise it may go again. might be worth a call to Dave Andrews (DVA) - very clued up and happy to give advice + can supply parts if necessary.
Followed you down Skipton road, Harrogate today......
Nice looking car, i was well impressed - right up to the point where you decided that it was perfectly ok to use the road as your own personal ash tray (flicking ash & then the cig but onto the floor)