Blown head gasket, likely cause????

There are no marks on any of the pistons to suggest it might have more serious damage.
He's bought one of those MSD all in one dizzys for it. (The one in the above link was a POS too.) The dizzy he's bought has the scope to limit timing etc. So, much tuning is going to be needed. It's not unreasonable to assume that, given the state of that fire ring, that oil could have been drawn in to the cylinder from the valley. He did have a grizzle that he thought there was more blowby than it should have had. But I'd say it was probably leaking out that gasket.