Today I made provision for a fuel return line in the end rib. I used a VA-112 flange and will thread a fitting in to the flange to accept the return line. I clamped the flange to the rib and match drilled all the rivet holes. Then I threaded the fitting in and used it to locate the center of the hole for the return. I used a unibit to enlarge the hole to 3/8.
I then countersunk the T-708 for the rivets to attach the nutplates for the fuel sender unit. I riveted on the nutplates to the inside of the T-708.
Finally, I riveted the platenuts and T-407 to the end rib. All of these will be covered by the tank sealant used to seal the fuel sender unit to the T-708 and the T-708 to the end rib so they did not require tank sealant.