There is what looks like a complete 67 GS 400 for sale on FB. It looks like he’s asking about $13k but taking offers. It’s a CA a black plate car. Sorry, I don’t know how to post a link from there but it’s on the 1966-67 Buick Special, Skylark and GS page.
He had it for sale once before on Facebook. that whole make an offer/ vague price thing is a big turn-off to a lot of guys