Just got a confirmation that the Chris Stephenson Bird is for sale.
https://www.facebook.com/chris.stephenson.338
But, if I were seriously lookin for one, & couldn't make a deal on that one, I'd first contact those who have raced one in recent years, but NOT the last season or 2.
A few names are:
(1) Bob Aceves
(2) Leo Glasbrenner
(3) Todd Hoven
(4) Brent Flynn
If this doesn't turn up anything, I'd check with all those currently running one. Sometimes racers keep an eye out for other cars similar to theirs.
I'm sure you know all these names. Besides Chris Stephenson, who has already been mentioned, some are:
(1) Randi Lyn Shipp
(2) Bryan Phillips
(3) John Schloe
(4) Tim Gillespie
(5) Adam Strang
(6) Ronald Prince
(7) Bruce Noland
And, I think Bob Michael may have built & sold more Pontiac Stock/SS cars than anybody else. He may know where something is.
I'd be surprised if you don't at least get some good leads from some of these racers.