The symptoms match lubrication failure, but nothing else that comes to mind. You have probably done serious damage to the aluminium bore, and may have scored the big end bearing as well. The cause was probably low oil - you don't run a splash-lubricated engine with the oil level down any more than 1/4" or so from full. It is just possible that the oil slinger on the timing gear drive was damaged, but since you know there was little or no oil in there, that is highly unlikely to have been the problem.
I agree with Joe - it's worth putting in the oil and seeing if it runs well enough to be worth keeping. Chances are it will never smile again, and will use some oil as well as having a rather tender big end bearing, but it might be useful for something.
