2-speed kickdowns are more available that TH 400 ones, but you are still talking about 45 year old electronic and plastic parts. If you are a purist, you have no choice. Otherwise both Lokar and B&M make aftermarket kickdowns.
I have the Lokar one, have not had a chance to try it out yet.
Which one do you have? Is it just the "switch"? I'm not that much of a purist, I want it to work for now...
