RE: ESM Dornier DO 335
Personally I am putting a cockpit in the one I have. Before I install it I will just reinforce the area with some 1/8" balsa glued/Epoxied to each side . Maybe a 4" wide piece that has been cut to exactly fit between the bulkheads. That will really strengthen the area. You could also use some carbon fiber glassed into the sides.. That bead you see in there is a bead of fiberglass and something like cabosil It should not ever move...
Ty