Had some time today so went out to the workshop and rivetted the gussets plates to the longeron and bulkheads.

This turned out to be a bit more work than expected (as always with airplane construction)

All attach rivets to the longeron can be squeezed with the pneumatic squeezer. So rapidally, all four gussets were attached to the longerons.

Then I realised that I had not read the plans sufficiently and discovered that the front, the F-656-L and R gussets attach to the F-706  bulkhead using AN426 countersunk rivets.

Damn... And I already attached the gussets... I used the pneumatic squeezer and hand squeezer to double dimple the F-706 bulkhead and F-656 at the same time. It worked fine but I shouldn't have gone through this hassle if I would have read better.

Next used the squeezer with G-yoke to rivet the middle rivet. Then realised that the inboard rivet can't be squeezed using the G yoke but needs a no nose set. Changed the head and rivetted those.
Then realised that the outboard rivets can't be set with the pneumatic squeezer as the longeron sits in the way. Had to pull out the rivet gun and then found out the round mushroom head doesn't really fit either.
Finally I used the back rivetting technique using the 12 inch back rivetter set and a bucking bar as backing plate on the AN426 head side to set the rivet. Djeeze... what a misery for such a small plate.

 The moved on the to the back gussets that hold bulkhead F-707. Same story hear for the pneumatic squeezing and used and offset AN470 universal head set for the rivet gun.

Final picture with all 4 installed.