I didn't see anyone mention this, but I thought I would let everyone know that I bought a day/night rearview mirror from a 1985 Nissan Sentra which I swapped the PAO arm onto and it fit just fine, the swivel ball was the same size. I actually could have just bolt it right up, since the arm is the same angle but I wanted to keep the silver OEM one. If you look up on eBay 1985-1990 (or possible other years) Nissan rearview mirror and you see the same bolt pattern (even the three screw pattern, which is the back plate on ours, it's probably the right size. Originally I found someone selling new Datsun Z mirrors on eBay which was a direct fit also, but the mirror was cheap garbage and the day/night setting didn't even work. because it was a plain mirror.
Anyways, hope this helps!
