Sorry to read this PiGo, it sounds like Simon is going to be busy soon..
Out of interest does it have the black plastic/alloy tanks like the Classic Morgans ?
I got 4 years and 26,000 miles out of the plastic one in my 4/4 Sport but many others weren't so lucky.
No idea actually the radiator sits quite deep in the cowl. The expansion tank is aluminium but the radiator looks like on top there is a black plastic cover.