1960s Stuck choke linkage in choke housing (Carter., '66 Eldorado)

[Julien Abrahams]

So, I am working on a '66 Eldorado. It has the Carter carb. The choke plate was completely stuck (open) and after investigating, I found that the things that are stuck are in the housing. So I removed the housing (which was easy as there are only three screws) while leaving the carb on the car.
There are two pieces that are stuck. First is the vacuum piston. Second is the small shaft that connects the piston and the thermostatic coil to the choke rod (that connects to the choke plate). I have tried: soaking it in penetrating oil (for a week), soaking it in acetone-trans fluid mix for a week, heat, tapping the "ear" (that the choke rod connects to). But, no matter what I do, I cannot seem to get it unstuck. It seems like it is rusted in place. In the image I indicated the shaft (that goes through the choke housing). The piston rod is connected to the shaft with a screw.
My question is: what to do now? I cannot replace it with an electric choke, because that shaft (which is stuck) needs to be able to rotate. :S.

[Michael Petti]

I have 2 Ideas. First is to contact a carburetor shop like Mike's Carburetor by E-mail and see if they have some pieces parts, they could send you. Your pictures are very descriptive of what you need. Second is to find a shop that could drill out the old shaft and fashion a new one for you.

[dadscad]

From the crud in the choke chamber, It appears that the heat tube in the manifold crossover has burned through allowing exhaust gas to be sucked into the choke chamber causing the damage. If it was my choke I would find a flat head screw that had the corect threads and was long enough to bottom out in the lever shaft and be long enough to also go the thickness of the housing bore. Support the housing on a couple of 2 x 4 blocks with the lever suspended in the gap between the two boards. Use a light weight dead blow hammer to tap on the head of the flathead screw to drive the shaft out of the housing. Be sure the screw goes to the bottom of the lever shaft to prevent damage to the threads.
You'll also need to repair the heat tube in the manifold. 
Hope this helps.