Firewall to tank box reinforced with tri-stock. Before assembling this area you need to determine if the engine that you are using will allow for the correct engine-thrust-plate-to-firewall-dimension. A YS 1.10 puts the thrust plate out an additional 1/2". Make sure that the cowl can accommodate the difference or cut the tank box back 1/2".

Landing gear plates (2 of em - 1/4" ply about 1" wide) are parallel and are notched into the former at the "wing bay", skipping a former, and terminates at a former of the tank box. Tri-stock was used to reinforce the formers - fore-n-aft at the notches. There is no "meat" to reinforce the ply to the sides. Guess you could load up balsa block around the plates. Perhaps you double the 1/4" ply plates with 1/8" ply. I chose to use the stock approach with a bit of tri-stock at the formers.

The wing's belly pan is pretty flimsy as the 4 rails are made of thin lite ply. Some have sheeted it. Mine were pretty wavy out of the box. Felt good just to get the darn things close.