M-seal obviously isn't the solution in this case; the problem can be in either of two places or both, the oil breather can be blocked and it creates an unnecessary pressure within the lubrication system and due to vibrations and loose screws/bolts the leaks are again obvious. It could be that if you've had excessive or continuous overheating, the seals are damaged too; also this is more of a rarity. You must try to reach those casing bolts in each side and you will probably find some quite loose, tide those bolts accordingly with the appropriate tools, wipe properly the area and monitor the leaks, very often as part of the service, those leaks are fixed but its wise to ask for a quote prior to service. You may be surprised and not be too expensive but with a guaranty.