Joe that's a nice color scheme . Easy to see. The area in front of the speed brakes on the older kits had a under camber . It effected landing in a bad way. People would fill it with the lightest product you can get. Balsa then glass would be the lightest. I did the hatch the way you stated. It only came off once. If you use about 10 MM of crow stall will not be a problem. When I was doing my first flights even with crow, flaps speed brakes the plane would get pitchy on landing. CG was right. I finally put 4 OZ lead in the nose and problem was solved. This is a plane that you never! let off the elevator on landing. Good Luck Dan