I know you probably already did this Don.
But I would check the crank real good where the seal seats on it.
Maybe even take a buffer pad and try to polish it up a little.
You know to make sure there is no ridge's or anything stuck to
the crank like rubber from the old seal. It almost makes me wonder if
it ain't out of round or got a nick or something.
I did have a freind that installed his in back wards but he had more then just a drip now and then. Next are you sure it is not comming from up above and running down?
I know I have had oil senders leak down like that before.
Just asking, I know you probably checked all that stuff.
Good luck Don; Hope you get it fixed this time.
Kurt