Traced the mirror image of the left T-405 onto the right bracket. Same process as the left, rough cut on the band saw, bench sander, and then the scotchbrite wheel. I then cut notches for the shop heads in the rib.
On my Craftsman drill press, the drill speed is controlled by the configuration of the belts and pulleys. I set it on the lowest rpm it is capable of - 250. I then got out the fly cutter, found the center of the cutout for the left inboard tank rib and clamped it all up on the drill press. The fly cutter I got only goes up to 4" diameter, which isn't really big enough. The operation was a non event. It cut well. Kind of loud though. I opened the hole up some more with die grinder. There is still a bit of the rib stiffening bead left. The plans show the rib hole slightly smaller then the doubler ring, but many builders seem to cut it the same size. I think mine is OK. The remaining bead does not interfere with the access plate.