After measuring and re-measuring at least six times, the improperly set rib is back in place correctly. I built a jig attached to the table to ensure the rib was in place and square, then epoxied in place.
I cut the tank supports 1/4" longrer than necessary ready to trim to the proper length one the final rib is set and the Butt Rib is in. I also attached the forward rubber cushion to the back of the spar for the tank to rest against.