Slipping in the wing saddle secondary ply reinforcements seal the deal for strength at the firewall landing gear mount and add surface area for the bottom sheeting . It also leaves the option to use a nylon bolt to hold the wing down in the rear should forego rubber bands. I dooo like bands they save wings! But like most of us designers we find them ugly fugly indeed. Note the firewall was shaped to suit the footprint of the most common round engine mount. I don't like square mounts as they tend to have you building box fuselages.
