2 angle stiffeners have to be cut to size from 063 angle 3/4 by 3/4. Very easy. These become F704-M
Mark the center line on the flange of the angle, look through the prepunched holes to center the centerline and clamp to F704-A in place.

Now matchdrill using F704-A as drill guide. The two holes attaching also F782B-L and R have to be drilled to #19 for AN515-8R8 screws.

The drilled holes... 

Then, use a plate nut or the plate nut jig tool to drill the 3/32" holes for the nutplate ears along the centerline on the angle. The nutplate attached to the angle only. 

Finally, countersink the nutplate ears on the stiffener angle. 

Drilled the snap bushing holes on the cover support ribs and reamed the holes to size.

Then started to rivet the side plates to the center sections.
The center ones can be squeezed. The top and bottom row are too close to the F704-F bars and must be shot. 

Nice view. I'm not very pleased with my 1/8" cup set for the AN470 rivets. It leaves a marking on the manufactured heads after squeezing. These were from Avery and are definitly not good quality.  

The picture below shows all rivets that can be squeezed using a 3" yoke. 

 Another shot after finishing the shooting of the remaining rivets with the gun. I did this by myself without a shooting partner. I'm pretty pleased with the progress I'm making on being able to deliver quality work when rivetting alone.

All the shop heads in close up. 

I also measured the control unit bars according to the plans. The hatched area has to be cut away for saving weight. I already drilled some 1/4" holes  to get a nice radius in the bend. The rest of the cutout will be done on a milling machine. The material is just too thick to cut with the band saw

Dimpled the nutplate ears on the cover support ribs. 

F704 is now ready for priming. I'll continue first with the next bulkhead: F705.