Okay, this is gonna be a bit difficult to explain, so I included some screenshots.
It's been awhile since I used Gmax, and I'm just getting back into the swing of it by throwing something together that I haven't worked on before. I'm testing my knowledge, sort of like.
So I get to the part where I'm cutting out the ailerons from the wings. My previous method was to create a full wing and then cut and detach the ailerons/flaps/etc using "Compound Object" and some splines.
So I tried this again, thinking it would work.
Unfortunately, I discovered that I don't remember how I got it right.
"A" IS THE PART CUT FROM THE WING.
"B" IS A CYLINDER I ADDED FOR VIEWING DURING ROTATION. 

The cylinder was modified to match the taper and skew of the aileron itself, and then attached. It should now be the axis of rotation, however,
I don't seem to remember which angle the axis should be at.
In the following image, the rotation is in line with the
axis of the cylinder (1). That is, the axis of the polys running right to left:

The problem here arises from
the sides of the aileron "pushing through" the sides of the aileron well (2).
In the following image, the rotation is in line with the
axis of the wing cutout (3) That is, the axis of the aileron itself, running from front to back:

The problem here arises from
a gap becoming visible as the aileron rotates (4).
So what do I do? How should I set the rotation? Or should I go back to square one? ANYTHING is helpful at this point . . .