The Skydart is one of my favorite glider kits. Maybe my #1 favorite. I liked the looks, and it was pretty reliable
I hope to attempt an RC version, soon (mid-2017).
Years ago I did a 2X Scale-up using mixed elevons. Worked nicely, but was a bit tricky due to the engine propellant mass being burned off. So if it was trimmed for the right glide CG, then it was tail-heavy at liftoff and trickier to keep the boost under control. If I moved the boost CG a bit more forward to make the boost easier, then it was nose-heavy for glide. If I did it over again, i'd probably use the water ballast trick, some water in the nose at liftoff, that drained the water during boost, so the glide CG was good and the boost CG was good. I used that method on a couple of models, my old X-1 and the booster for the Orbital Skydart Project.
The wing on the 2X model was .55" thick blue foam. With slightly rounded edges, being that thick the glide was not as good as it could have been if i'd used something thinner to make the wing, like say 1/4" balsa. Or use Depron Foam as Frank Burke does on so many great models, and add some fiberglass cloth to the leading edge for ding resistance (or simply inset some balsa for the first 1/2"-1" or so of the leading edge, the rest as Depron.
Also if i made another, I'd probably make it smaller than 2X. Such as 1.6X using a BT-60, or maybe a bit smaller if I wanted to only fly it on 18mm C6 power (probably 1.3x to 1.4X using BT-55). Although, 2X was about right for D12 power, as far as D12 boost velocity, at a glide mass of about 11 ounces. But that was a bit overweight for D7 and E6 reloads. So, on second thought, if i did a new one, smaller would mean committing to at most C6 power (Could consider D7 and E6 loads, but the cost these days..... sizing for C6 is very attractive).
Might be possible to do with an internal pop-pod, put all the radio gear (the smallest and lightest practical) into a blow-molded nose cone, including one rudder servo (but would have to add a lot of tailweight to balance it out). Or, maybe put R/C inside the cardboard side air scoops that I never have bothered to use.....but that could indeed be the way to go for R/C and still use an internal pop-pod. Yeah. Never thought of that until now.
I did make up a BT-50 sized test model using just rudder-only to steer it, and rudder-only worked. But the radio gear and servo were inside of the BT-50, so the only way I flew it was piggybacked on a D12 powered rocket. Actually what I really wanted to do was two BT-50 Skydarts of different colors, on both sides of that booster, so after ejection there would be two R/C Skydarts flying back, with a 2nd pilot flying the other one.
2X Skydart info:
https://georgesrockets.com/GRP/GLIDERS/skydart/skydart.htm
OSP info:
https://georgesrockets.com/GRP/GLIDERS/OSP/OSP.htm
Rudder only BT-50 model for "Skydart Twins":
https://georgesrockets.com/GRP/GLIDERS/Twingliders.htm