Have you verified that it is the main seal leaking and not the side seals leaking? If not do that first before trying again. If it is the main seal it will leak out onto the crankshaft flange and the oil will be slung out onto the flex plate and outwards from their scope If it is leaking out of the side seals it won't be on the crank flange scope up
I haven't had a rear seal leak in a lot of years, 100s of BB built.
Let us know what you find out, maybe I can help you stop this up

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)