Obviously the debri wouldnt have done the world of good , coming loose .
Typical if stored without a Tank of No Nitro fuel run thru , to clear the Nitro residue . Before long term storage .
Seems half the pre used engines you see suffer this .
And if Ball race the STEEL Bearings are often rotted / rusted . Tho the tracks being shiny are the last to go .
The debris comming off with the heat & pressure cycles , from running , will lead to tears .
And likely scour the Liner & shaft bearing . Result = scrap metal .
Clean with green 3M pads & elbow grease . . If youve a polishing wheel , dont let me stop you .
The aluminum seems to syurvive much better . But still can be badly pitted / eroded . Particularly from dampness .
PLUS , the Conrod Top oil hole , was blocked with coagulated castor oil .
The Datk stuff on the front of the flywheel is C R C gook & light surface oxidation . Will polish off . Left its debri .