Yours is both old and brutalised (pushrod bent improperly). Either get an original-type replacement from Old Car Parts Northwest, or get a № 1231 electric choke kit, which will bolt right on and hook right up and allow for much easier choke adjustments (since you don't have to remove it to adjust it, like you do with the original type).
Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download. And you'l find tune-up parts and technique suggestions in this post.
