What is this throttle mount?

I am looking for something like this - sorry about the blurry pics - I stole them off a Craigslist ad in Texas. What is this mount in the first three pictures? Is there anywhere I might find one?


Here (last picture) is the linkage that came on MY slant six and is unsatisfactory with the carb and kickdown (Holley 2209?).
Thanks for your knowledge!