More on the Mach I
I recall it had a foam wing core and the stab also has a foam core and the stab had a beautiful symetrical airfoil shape.
The tail was a little long for planes at the time and the 'Mach I' was expected to fly fast and very smooth in patterns.
I believe it had three bolts with recessed heads to hold the wing in place. Two up front and one in the back.