2003 Bonneville Carburator (keihin Cvk 36)

Hello all. I'm having a hell of a time trying to source an air valve diaphragm for my carburetor. The strange thing is, the PDF diagram of the of the carb (Exhibit 1) acts like this diagram does not exist. it should be showing the parts in the center right of the pic close to the choke lever. I cannot find a part number. But the valve, spring, diaphragm and seal are all real parts. Below you can see a pic of the section in the left carb cut out for the diaphragm and spring (Exhibit 2).

I thought I found the right diaphragm, but it turns out it was for a CVK 40 carb (not my 36 carb). The stem on the diaphragm was too stubby (Exhibit 3. Correct, old diaphragm on the top. New, incorrect diaphragm on the bottom). I'm at a loss as how to source this part. Any suggestions? Note: the only reason I think I have the CVK 36 carbs is because Chat GPT said that's what a 2003 Bonneville has. I couldn't find and article or post that said anything specific.

Exhibit 1



Exhibit 2


Exhibit 3