Slant six heat riser

Yes, I understand it's function and relationship to proper choke operation. Unfortunately, it was stuck closed, as I suspected. The carb was getting HOT, which led me to suspect the riser. So, now I just have to allow an even more ample warm-up until I can scrounge a new spring and coil. Since it does rotate with a little help from pliers, I should be able to free the rust once I find one, saving me from pulling the manifolds. Does anyone know where I might find a new spring? My choke spring is a bit oxidized as well and also tends to stick. Prompting me to tap the pedal at times.