There are 4 doublers that reinforce the landing gear channel - one for each corner. These were drilled previously.
Finished debur of them, followed by riveting them in place - 11 A5 rivets in each one, followed by an A3-3A bolt in the last inboard hole on each doubler. The outer two holes in each doubler will be bolted when the landing gear weldments are installed after the fuselage is re-mated.