I clecoed the bottom forward skin back on and pulled out the floor stiffeners. Just like the side skin stiffeners, I had to use my hand squeezer and a couple of scrap pieces of angle to get these to sit flat on both the skin and the angle. The forward ends of the two center stiffeners also needed small relief cuts to clear one of the firewall stiffeners.
After confirming sufficient edge distance on the skin holes, I match drilled the stiffeners to the skins.
Here is a shot of the inside. The clamps holding these stiffeners to the beefy angle on the firewall and the cover support ribs on F-704 still need to be drilled. That will tie all of these structures together quite firmly.
