We used to build our own RV's...
I helped build a couple using plans from Glen-L
. Somewhere I have pictures of them. Helped build a houseboat from their plans too. The new units are much more complicated and better suited to a factory built environment. Unfortunately the workforce skill levels haven't caught up.
I don't know what the answer is to the current state of the RV industry. It is interesting (in a perverse way) to see what they are doing and wait for the implosion. Dutchmen was one, that if they had not been under the Thor umbrella and had the Keystone management available to take over, was headed for the crap pile.