Mid-fuselage ribs riveting done, skins started

We finished riveting fuselage bulkhead and baggage ribs:

All mid-fuselage ribs and bulkhead riveted in place

I clecoed the bottom skins on and final-drilled all the holes:

Mid-fuselage section with skins on

The floor stiffeners required some fluting to line up properly, then they were final-drilled as well:

Floor stiffeners, fluted and final-drilled in place

Mid-fuselage section with skins and floor stiffeners only (it barely clears the ceiling!)

I found that the holes from the skin to the outboard seat ribs don't align :( so I'll need to flute that part, which will be especially tricky with it already riveted in place:

Since I only have a vise-grip-style fluting plier, which would be even harder to use in this space, I've ordered a regular plier from Spruce and will give that a try when it gets here - I have plenty of other holes and edges to deburr in the meantime.

Time lapse:

Total mid-fuselage ribs and bottom skins rivets: 412
Total mid-fuselage ribs and bottom skins time: 67.5h