The basic fuselage structure is a straight forward build. Left and right fuselage sides are framed up and then brought together with the cabin bulkhead, formers and cross members. The structure becomes very rigid once the tail end is brought together and the firewall is addded.

Here's a shot of the front end. The kit manufacturer provided two pieces of 3/32" cheap doorskin plywood (to be laminated together) for the firewall. This was replaced with a single piece of 1/4" birch aircraft plywood (5-ply).

1/4" sheeting added to forward fuselage.

This is the top of the cabin where the wing center section is mounted. I've tapered the aft ends of the mounting blocks to save a little weight.

After assembly, I had second thoughts about the structural integrity of the loadbearing cabin side frames. To "fix" this, I strenghtened the cabin frames by running carbon fiber tows through the wing saddle and down the cabin uprights. The forward pair (left and right) are anchored to the upper left and right corners of fuselage former F2, while the aft pair run to the bottom of the fuselage sides. The carbon tows are sandwiched between the vertical members of the cabin sides and Lite-ply doublers.