The A-4 Skyhawk has a similar setup. The A-4 stab is used to trim while the elevator is used for control. The big difference between the two designs is the A-4 is subsonic and the Super-E is supersonic.

I have a friend who flew the Super-E for the Argentine navy. I'll e-mail him the question and pass along his reply. This may take a few days.

I have always wanted to model this plane. It's going to make a great project!

Tom