I can sort of understand that. If my theory is correct the power for the couch did not exist in the full time bed version of the Serenity, so it would need a high power branch off the circuit breakers run around the entire side and behind the shower, and switches installed to control it. That is a LOT of work, and would require painful disassembly of the shower area and kitchen.
If there WAS a couch there and it is missing perhaps it could be replaced by one someone else is taking out, but it may be a LONG time to find that.
A short term solution is hitting up Ikea or one of those RV recycler's like our local RV Dr. George and find a piece that will fit. It won't have the funky mechanism that folds down after completely filling the space. If you REALLY wanna get the original one than do the 1200 mile drive. I hope to do the same this spring and have them work on my Serenity. Although I don't know what that would cost, gotta be outrageous.
-Randy