Welcome to the forum GB, your 80 has the same kilometerage as mine, but thankfully the head gasket on mine is still intact.
Do you know what caused it to blow? Coolant leaks, overheating, etc?
Next question is it petrol or diesel and if diesel, HDJ (with turbo) or HZJ (no Turbo)?
I‘d be inclined to want to fix it, but it depends on what caused the gasket to let go. It could be almost anything from a cracked head, warped head, failed gasket, even a cracked block...
It also depends where you are in OZ, the availability of spares, second-hand parts etc.
So it’s hard to offer advice, really.