Just last night, I hit the jackpot myself.
Using a name I pulled off a photocopy of a Polaroid of the P-O-P for my 67 Yenko, I contacted the original owner on the first attempt. As in turns out, the original owner lives 3-4 miles from the address listed on the P-O-P, near Madison WI. His name (Gregg spelled with two g's) made it easy to find him in the telephone listings. Total research time: about 30 minutes.
What a blast! Prior to this phone call, I don't think we knew anything about the car before 1990.
I got to confirm what kind of badging was used on the car (no YSC emblems, only the 427 badge on the fenders like in the Span Inc photo -- plus something on the hood he can't quite remember), the correct spare (Charley, you might be getting your SpaceSaver back

), how fast it ran (low 11's with slicks), and more. He promised to try to find some original photos which, unfortunately, his ex might have. Been there, done that.
So now I want to trace it forward from the original owner. He sold it a couple of years later to a local mechanic/racer who drag raced out of Union Grove in the early 70's. His nickname was "Coke Bottles" because of the thick glasses. Any of you 'old guys' remember who this might be?
I'm thinking maybe it would be nice to reunite the original owner with the car at the SuperCar reunion, and maybe see if it still runs as hard as it used to. That'll give the trailer queens a conniption fit, don't you think?