Purchase the manual wiper for the 2A, then shorten the wiper arm to fit the 3A windshield.
I thought the manual wiper for the 3A was the same as the 3B. When I see images like the one posted here:
http://www.cj3apage.com/3Ayabbfiles26/Attachments/image_112.jpgit reinforces my view that the arm is longer (not shorter) than the 2A version (the version available from vendors).
Comparing the two versions side-by-side is a challenge and a quick measurement of the arm length could verify the correct arm. Comparison here:
http://cj3b.info/Tech/WiperManual.htmlI may be wrong but if the arm is shortened further, you'd be moving the blade real close to the shaft. The above 3A image from the outside seems to indicate the blade is closer to the halfway mark on the arm - indicating a longer than 2A arm. IF that's the case, then cutting and welding a splice in a shorter available arm is a quick fix.