I built and flew a SS2 model. 1" diameter with a 13mm motor mount. Goes about 300' high on A motors. I think it's the first flying SS2 model out there.
There were a lot of concept pictures and such out months before the actual ship was unveiled. Mine's by no means a perfect scale model, and the huge eye pattern is well-nigh impossible to recreate, but it looks pretty good.
I used about half an ounce of nose weight and it's very stable. The nose cone is an Apogee cone; the tail cone I cut myself from an old broken cone. I wasn't able to recreate the cockpit bump on the nose.
It's about a 1:90 scale. The SS2 is about 60' long, with only 16' of that actual cylindrical body.
(from my bloggy blog) has basic scale information, drawings, and a discussion of the "DNA of Flight" - the drawings of aviation milestones on the spine of SS2.
Ran Barton's discussion
of the DNA of Flight
The one problem with the SS2 is the small nozzle on the original - just one-third the body width. That means a 1.5" rocket for a 13mm motor, 2.2" for 18mm, 2.6" for 24mm, or 4" for 29mm. Even a half-width nozzle like mine is somewhat underpowered.