Your leak is probably coming past the input shaft seal of the gearbox, but it's also possible to be coming from around the threads of some of the bolts that attach the bell housing to the gearbox. These bolts (two, as I recall) penetrate into the gearbox oil sump. Make sure you seal those threads well whenever you reinstall the bell housing.
Tom, I have your BJ8 included in the BJ8 Registry from AHCA records, but there are additional details I would like to record, if you would contact me directly:
sbyers@ec.rr.com.
For the benefit of those who do not know and who might be interested, the registry has added two more "new" cars to the record today, bringing the total now included to 8,533 BJ8s worldwide (48% of total original production).
Thanks!