I just scrolled through the entire thread and I'm surprised that everyone has overlooked another leak source coming from the same area as the rear main seal... That is the flywheel bolts. The flywheel bolt threads go through the crank flange. If the bolts are installed without thread sealant, oil will migrate past the threads and act like a real seal leak. In any case, spray the entire engine down with something like Foamy Engine Cleaner [I like it because it dissolves oil and sludge quickly] then hit it with a car wash pressure nozzle to clear off all the oil you can... Pull the lower flywheel cover [4 bolts, if they are all still there] and run the engine for a bit. use a good flashlight and look up at the flywheel/block area for fresh oil drip.. In either case, main seal or flywheel bolts... both are going to come out and be re-sealed.. Good luck.