Picked up the Barracuda! Love my first early-A :)

Those chokes are pretty reliable if you don't fool with them. I the choke is truly bad, I've seen new (NOS) ones for sale on E-bay from time to time. More than likely it's an adjustment problem or the crossover is plugged and not allowing the choke to heat up. You can check that by touch (carefully!) After you fire the engine up cold, feel the intake around the choke well and see if it heats up fairly quickly. When warm it should be way to hot to touch so be aware. The choke pull-off only comes into play when the engine is at less than full operating temperature. The diaphram is easy to test. Pull the hose off and push the plunger in. Hold your finger over the hose nipple and release the plunger. It should stay were it is until you remove your finger from over the hole and it returns to it's original position. You adjust the amount of pull-off by bending the link between the pull-off and the choke plate tab. When the engine is cold, the choke should close completely after one pump of the throttle. After the engine fires up, the choke pull-off should move the choke plate open slightly to allow more air inside. Usually the adjustment is 3/16 to 1/4" or so but you may have to play with that for the best idle depending on your engine/carb specs and fuel used. I know, it's pretty low tech but once it's set correctly, you shouldn't have to mess with it again unless you modify something.