ok after doing some checking KMP does not make an extra 300l in any size.However CMP does.they have at least 3 sizes.the specs for the .50 size are.
Wingspan
1430mm Length
1270mm Weight
2.85~2.95 kg Wing Loading
92~95 dm/2 Airfoil
Naca 0014 Wing Area
30.8 dm/2
in english units that is about 3.84 sq ft and 104 oz for a wing loading of 27 oz/sq ft.also notice the airfoil.it is 14 % thick so a bit thinner than sport planes that are 15-18 % thick.this wing loading is more in the scale plane range than aerobatic.to get this in an acceptable range the weight would have to be around 4 pounds empty.