Rob, thanks for the offer, but no worries, the advice on this thread is payment enough for me.
I took some more pics today, here they are:
I think those burns prove that oil could not get through, and that cylinder and piston got hotter than I care to imagine.
(All of the gap are on the top in all pics)
No rings, notice the larger gap on the top of the pic. I hope that's the piston deformed and not the cylinder. I'll take measurements soon.