I believe that you will find that you really want / need the wings jigged up and completed to the point of tank baffle - rib - skin - Z bracket fitting on the spars and outboard leading edges in order to achieve the desired results for Z-bracket layout, alignment and drilling. My $0.015
I do appreciate your desire to conserve work-space. I am building in a compact single car garage sized space (because it is just on the other side of the wall from my living room) and keeps me within EASY reach of my project!
Good Luck and keep pounding those rivets as we say.