Here's the auction results with some updates on the comments. Prices include buyer's premium of 10%. Divide by 1.1 to get hammer price.
Lot 185 (Thursday, mid afternoon*) Arntz. Car was not present yet. Update: Car was a disaster. It looked like it was painted in an open garage during a dust storm. Final price 26,400.
Lot 343 (Friday, late morning) CCX. Car was not present yet. Update: Car was well done with very good paint. 53,900.00
Lot 374 (Friday, early-mid afternoon) Unique. Good looking car. 42,900.00
Lot 395 (Friday, late afternoon) Factory Five. Good looking car. One of the best FFs I've seen. 42,900.00
Lot 424.1 (Friday, late afternoon) SPF(?) car wasn't yet present and docket description doesn't list original mfgr but lists as "rolling chassis" and mentions SPF side pipes. Update: I looked at this and it was a most excellent looking car. I think the buyer will be very happy. 63,800.00
Lot 640.1 (Saturday, late morning) Factory 5. Car was there. But wheels and engine are clearly "custom". I think the deviation from "cobraness" hurt this one alot. 29,150.00
Lot 720 (Saturday, late afternoon, early evening) Shelby CSX4000. Nice looking example located in showcase area. Update: I was on the block for this. This Cobra was a pair from the same owner that also sold a Series 1 just before. They really hyped the Series 1 but it felt to me that they took time down on the Cobra after the Series 1 to keep time on track. It is repainted to the S1 color. 82,500.00
Lot 735 [correct lot number] (Saturday, late afternoon-early evening) Shelby CSX6124 (new from Planet Cobra, Stephen Becker). It is a new car. Update: To me this was the best prepared car, but it is brand new. 134,200.00
Lot 752.1 (Saturday early evening) Shelby CSX4380. Nice looking car. 74,800.00
So, Shelby branded cars get high prices.
But what matters most is quality. Build an excellent <anything> and your work is rewarded.