Lots of deburring of holes and edges. Also took some time to enlarge the molex connector hole in the aft deck and doubler to accomodate a 9-pin CPC connector instead. A 3/4 inch hole was used and is slightly larger than needed, but effective. Will also need to modify the flange of one longeron at a later date and adjust rivet lengths.
To get a center hole I sandwiched a piece of flat aluminum between the doubler and aft deck before drilling a #30 hole that was then enlarged to a 3/4" hole with a step drill bit. Rather effective.