After gluing all cross-breams and laser cut balsa, I started working on the tail block, which consists of multiple layers of balsa, recessed to accept the ply tail skid attachment point, sandwiched, and than later on tapered to fit the shape of the tail. It also functions as a guide to glue the longers to:

Recessing is finished, I only need to taper them now:

I also glued on the reinforcements for the frame. They act as a triangle supported the frame, and also to hold the cross beams in place between the fuse sides:

And after a few evenings of gluing, this is the result, ready for the lower longeron to be attached:

And a few close-ups of the work up until now:

I will not glue in the tail block now, I’ll safe that for after bending the fuse sides together, to be able to position it correctly, not depending on how the bend turns out.