But that is more severe and obvious than I've seen before so don't assume nothing else is wrong, did the cooling hold pressure before you dismantled the thing?
I don't know, I've only just taken delivery of it. It was apparently a good runner, but has a worn cam and a taste for oil. The heads and pistons are fairly caked in burnt oil so I assume the rings are shot.
Well the black colour in the valley area but the apparent lack of other built up crud would go with it being soot contamination from the gasket blowing.
Piston crown wet with oil would support the rings being shot, what are the valve guide like? probably shot too...
If that motor is sourced from a TVR then heads will be Will ringed with copper head gaskets as I remember, this is bespoke TVR and in that pic that head gasket looks copper unless I am mistaken, Spend on here knows all about this TVR mod or speak to V8 Developments.