It's not fuel. There are two bilge compartments
forward and downhill of the tank and aft of the bilges with the oil. On inspection and clean out yesterday, these contained only seawater. it looks like the PO was just dumping the oil in the bilges under the engine when changing it. It's impossible to see into these bilges from the aft access or the cabin so who knows how long it's been sitting there. The recent leaking may have cause those to overflow to the bilge pump well. I think my only course is to fill the engine with oil, start it and shine my spotlight under there to see where it's coming from.