I bought a 200 Sil casing from Scooter Restorations a few years ago that was being sold as damage repairable, one of the bearing drive plate screw threads had been tapped in too far & broke through into the chain case side, it had already been ali welded when I purchased it, I still run this engine now & fingers X have not had any issues so far, I know MB's are good & know their stuff but maybe contact some other places such as Oiltek or CS Engineering before deciding what to do next . Good luck
