I'll take some pics and give you a price when I get off work tomorrow.
It was on the car when I bought it in 2000, and I drove it for two years, then pulled the engine in 2003. I'm pretty sure it was a stock '66 linkage with the spring that went to the exhaust manifold.
It was a Mustang Monthly car, and I have a 1997 issue where they took the Motorcraft carb off and put a correct Autolite on; but it had the Motorcraft when I bought it.