I suppose another possibility is the camshaft seized to the head.
Need to get in there and see if the crank will move at all by hand, and if not, try to determine what's holding it. Seized crank, probably will see no movement. Piston or cam, should be able to rock the crank very, very slightly.
I'm not saying 100% it's seized, but the starter and pull rope both failing upon engine stall, is very suspicious.
Should also include engine driven pumps .. oil pump and water pump. If locked up, engine shouldn't roll over. Then if it's an automatic trans, more to consider, but the auto trans on these is out of my realm.