No support required, recommend 0.15mm layers or less.

Maybe slide the horizontal stab all the way through the holes one sides at a time to make sure it fits.

Put heavy things in the inside hidden square holes, nuts&bolts, metal, etc to counter balance the tail.

Glue the sides together, using filament pieces as alignment pins in the 3 holes. Glue on cross-tubes(longer one in the front) and then skids. One more pin in the middle of the Fenestron.

.Step/.f3d files for mods.