That was one of the websites I called. I waited over 2 hours on the phone to speak with someone. That person put me on hold and the automated service hung up on me.
I was thinking this should work.
https://www.mfgsupply.com/97973-warner-5218-45.html
It looks like it would spec-wise. I'm not sure what a "a/b" belt is? Is that a size or a style? I called this website and the representative said they just sell parts they wouldn't know if it would work for me.