Leak coming from A833 bell housing. Help!

Years sgo, I installed a "Professionally" assembled short block into my Demon...
Unfortunately one half of the rear main seal had been installed backwards...
Nothing but denial from the machine shop AND the seller.
Sure was a terrific oil-bath inside the scatter shield, and a quick way to mess up a new clutch disc...
Check EVERYTHING you reasonably can while you have it apart!