Worked on the MID SEAT RAIL SUPPORTS . The flanges required some small trimming. Then riveted the parts together. Plans say to set aside for later installation. Removed the Fuel Flow Transducer Bracket. The location I'm planning is mounted on the engine, so this will not be needed. I'll have to fill those holes in the bottom skin. Removed the baggage door. Then dimpled and clecoed the the baggage door shims in place. Continuing along, I started to rivet the forward floor skins using pulled rivets. I found that removing the UPPER FORWARD FUSELAGE ASSEMBLY helped to gain easy access. It had to come off anyway. Holes for the CS4-4 rivets were already drilled and dimpled. But the LP4-3s will need to be final drilled.