The gunk ( Carbon ) on the top is normal, due to all the different additives in modern gas. You do however have quite a lot of blow by. ( rings not holding back the pressure) Which is then caking the oil channel in the lube ring...which then further decimates the lube process. This much blow by would have been visible in the exhaust, I would think. Did you notice any " abnormal engine behavior"....or did you just decide to tear into the motor for the fun of it....????