Well, a few interesting things have happened since February. The previous owner of this Chevelle consigned the car, and although I considered making a deal on it, it sold too quickly for me to get off my butt and get it done. The new owner of the car contacted me out of the blue, from my old Ebay ad, and it turns out he lives about an hour north of me. We made a deal on the engine and he picked it up this morning. We were both pretty elated to reunite the engine with the car...they have been separated for at least 39 years.
So, there is one more LS6 car out there with the born-with engine. Pretty good day if you ask me.