I used the CNC mill to make these parts. The cover plates were made from from 0.025", the guide tabs are 0.063" and the guides are 0.125" aluminum. The fuel cover slides toward the trailing edge of the wing into a bracket that has been riveted to the bottom side of the wing skin. The front part of the fuel cap cover that has the tab is secured to the wing skin using a thumb screw that screws into a nut plate on the under side of the wing. I will have to repaint the cover, but overall the tolerances are great and there is little friction inserting and removing the cover plate, very pleased with the results. Next project is making a new wheel well followed by the engine mount.
