OK...I've been through the whole lower end...and the ONLY place there is this 'slime' in inside the cover on the clutch where the actuator is.
It does NOT seem like ChocoMilk from oil/coolant mixing...it seems like a vasoline/lithium grease. Again...the rest of the clutch and bottom end is free of this....'residue'.
::Shrug::
I think the previous owner thought it would would be a good idea to lube the actuator arm...I guess.
The clutch WAS slipping at speed...but that is due for sure to the springs/plates being stock on a BB351, so I will replace them with some stiffer ones. I'll update this after I reassemble and test some more.