Welcome aboard, RV Lovers!
RV manufacturers don't stock a lot of furnture, so its probably long gone. They get it made as needed, by companies such as Flexsteel for the driver/passenger seats and their own cabinet shop for the built in furnishings. Upholstery is typically contracted to local shops, using materials bought in bulk rolls by the factory. It was hard enough to get replacement pieces when they were in business (we had a 2002 Dolphin), so now I expect it is nigh impossible.
Most any local upholstery shop can redo your dinette seating, and any free standing piece too.
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL