Good idea to call them, they have always been good with me. You could try Ebay or a google search with that part# for the used option. Maybe someone will jump in with some options reference the used parts idea, as I mentioned before, I usually buy new or rebuild myself.
Have you considered rebuilding it? Or is it beyond that?
As far as another carb, I'm sure there is something else you could use, I just do not have a reference for it available at this time. I'll probably keep poking around to see if I could find something unless someone else jumps in with an answer.