George,
If the dye test doesn't work, find a shop that can do a "smoke test". This is the newest way of finding leaks in any engine system, be it
oil, coolant, refrigerant or whatever. Smoke can find smaller passages to get out of an enclosed system than does any liquid without making a mess, so smoke would be your best shot at locating your troublesome leak.
In your situation, I suspect they would inject the smoke into the crankcase and study the area immediately around where you suspect the
oil is coming from. It shouldn't take long for the leak to be pinpointed.