After cleaning the edges of the new ordered F713s and F7101s, drew a centerline on the aux longerons (the correct way this time !) and positioned them on the side skin.

Drilled them in place.  I then installed the F7101 grear attach brackets and drilled the upper line (through F713) in place. That made it easy to position the F717 lower longeron.

Clamped it firmly in place. As he manual says, it extends about 1/8" below the side skin. Make sure the lower longeron is parallel with the skin.

The 5 holes aft near the F704 bulkhead will be getting larger holes for AN3 bolts because of the F7114-L fuselage gusset that will go in there. As I'm building a taildragger, I don't have the gear legs in that position but on the engine mount. I just drilled them #30 for now and will work on them later when mounting the gusset. (just have to remember not to dimple those)

drilled the line up to the lower steel engine mount bracket.

rear view.

Important update 9/12/2018 : This is a great point to fit the F-7114 fuselage gussets. They are never mentioned in the manual when to install and when you realise you need them, it will be a more difficult fit.
So at this point, edge deburr the F-7114 L and R and check the fit on the mating with the F-704 wing mount holes and the F7101 gear attach webs. I started mine when the bottom skin and side skin where already fitted on and had a lot of work getting them in good alignment. Now you can still stand inside and have a close look. So do yourself a favor and fit them now. I would wait until the bottom skin is temporarily clecoed in place to do the final drilling of the five bolts through the F-7101's.

Then firmly clamped the lower longeron to the engine mount bracket. The engine mount is slightly tilted at an angle so this is why you had to twist the lower longeron earlier on.

Drilled one #30, put a cleco in, move the clamp, thighten again and drill another on.

Inside view of the same process. As you can see, nice full surface contact between longeron and bracket.

No more clamps in the next shot. The lower engine bracket finally fully drilled to the structure.

All holes look great, no elongation.

By drilling the lower longeron to the skin, also the gear attach web bottom row is drilled.

Repeated the same process on the left side. I won't repeat the step but here are some shots of the finished work.

Now we are back to where I was and I can start working on the tank attach brackets again in the next session.