The early 190s like in 2005 used what Roadtrek called a "permanent" armoire in place of the 3rd seat on the passenger side. A year or two later they switched to a third seat and armoir that interchanged easily on the same base. The later ones are much easier to switch out either way.
Persoanlly, I really like the older armoir as it has lots of space in it, including drawers. I don't know how hare it would be to get out and put in a seat, but it would have to be removed from the floor. You would also need the seat base and the seat belts to complete the swap. Hopefully, they didn't cut off or remove the seat belt mounts to put in the "permanent" armoir.