Blown head gasket on Disco 300tdi ES

Hi. Would like your opinion on whether or not it's worth replacing head gasket and what are the pitfalls/problems that could potentially be.
Radiator replacement, being one.
Heater-guage showed no sign of overheating but oil light came on only at roundabouts, only just before it came to a stop.
Disco wasn't out of oil but no water.
Don't know if it was a hose, rad-leak, or my fault.
Any knowledge of probs?

if iit stopped the engine it the pistons must have nipped up in the bores you wont know if theres any damage til the heads off,presumably it turns over now

Its got to be a maintenance failure. Not had a 300 but the 200 could withstand all manner of abuse and still keep going.
Bloody simple engine to rebuild from scratch. Did mine for little money but that was just to ensure the 250k miler was still good and it was.
Someone has a blinding motor somewhere.

Best to ask over in the disco section of the form, you will get more help, this is the members projects section.