I am away from my camper for a couple weeks but I believe these are the hinged folding brackets FWC uses. Attached to the couch then bolted to a heavy gauge L type bracket which is bolted to a base platform.
Or ... this could be all that you need.
I know FWC sells all or part of the assembly for quite a bit.
In a couple weeks I can check out my camper, which is brand new to me, and possible be more specific.