Welcome to the forums. Too bad you are not in California another new member there was talking about taking out their bathroom sink. Still these parts can be found. Talk to "Balrgn" he has an Argosy that he's parting out in New Hampshire maybe the sink can be fitted. If it can be done he can do it. You can PM, (private message ) him or I bet he will just pop up on this thread.
Good luck to you.
1994 30' Excella 1000, Chummy III- Ford Excursion- 7.3 Turbo-diesel