A little more re weight. For a "typical" Scientific Log with a 18" span and about a 3" chord, you can get an unfinished fuselage with firewall attached down below 10 grams, if you use contest balsa, and do a lot of hollowing. The wing, using the same balsa, also can come in around 8 grams or so. Indoor Peanut tissue paper can add strength with hardly any weight gain. Also, you can tint clear with Rit dye for a light finish, and actually brush it on (the Rit dyed thinned clear seems to clog spray systems easily). Yes, weight is very critical, especially for Stunt. It is somewhat critical for NVCL proto Speed rules, and not as critical for Kalamazoo rules, which uses a pure speed timing. However, a few extra grams, invested in areas that strengthen the model, will not hurt in Team Race, where pit time is the critical variable.
The Bel Air was mentioned previously. I built a kit version and competed in Team Race before it was made illegal. The wing can best be characterized as clamshell construction. You can fly it in Unlimited now, and should stunt well.
Currell Pattie