Stan, I noticed the 12v auxillary system you have. I haven't needed an extra 12v system yet. I do throw the house battery from my Casita into the van when I think I'm going to be away from a jump start. I'd hate to kill a battery several miles down some back road so a spare is a good idea but I've never really considered wiring one in permanently. Well, not yet anyway.. I did just order a small 12v fan so that idea might change. I like the idea of a solar charger and deep cycle battery for the fan and it could be used to jump start the van in an emergency.
I like the table you had on the spare. That did get to thinking about my "kitchen" setup!