I had one of those when it first came out. I only applied the cockpit windows and it practically needed no trimming out of the box. It had several successful flights with good glides, including one where it did a carrier landing on the roof of a friend's Chevy Suburban. Eventually though after about nine flights it retired itself. You can't really put recovery wadding in this bird because it then becomes nose heavy. What happened was during ejections, the nose cavity would erode slightly each time until the nose came completely off. It still glided on that flight, just doing stalls on the way down. The damage was potentially repairable, but I never got around to doing it since it would eventually blow off the nose again anyway.
BTW, my model never went unstable on boost. Sometimes it would do a slightly wide spin on ascent, but it never went sideways like an Estes shuttle with boosters kit I had did on its only two flights.