Wood removal

OhBee,
A little late now, but this is where a home-made notching tool would help. Mine is an old hacksaw blade piece about 7" long, with fences super glued to either side of the blade. The fences keep the blade from cutting too deeply. If the wing is truly just a rectangle, then the leading edge and trailing edge are set side-by-side, and the rib notches are cut into both pieces at once. If the rib is thicker, double up your hacksaw blades. My thicker one has two blades with the teeth cutting in each direction.
Then it is just a process to trim the LE/TE with a small hobby wood plane. I have two planes. One is an antique that uses my cast-off DE razors (too dull for face is just fine for balsa wood). The other is a newer one from Lowe's...a cheapie that can be resharpened.

It appears to me that this wing will then have fairly flat wing tips with very blunt, but rounded edges around the wing tips.

Looking good, OhBee!
The Kobalt is a Lowe's item...$11. Depth of cut is adjustable, but the knife edge needs to be dressed from time to time. I'm getting better at sharpening it.
The WilKro is an antique picked up on eBay. I like it because it uses my DE razor blades (after they lose too much edge for my face). It can be re-configured as a bull-nose, a spoke-shave, or long like it is here. Depth of cut can't be changed very much. But it would cut potatoes thinly enough to make almost see through potato chips!