As far as trying to make your own aerofoil, I think it would be very difficult. I think aconsola's idea is probably right, that this form was made in a longer length, then cut into smaller pieces. Like I said, the two sides are fused together, I've never seen that on anything lexan before. You might be able to bend lexan around and glue or screw it to itself on the other side. It would probably take quite a bit of trial and error, and even then I think it would be very difficult to make the aerofoil shape. I think you'd probably have much better luck if you tried it with a piece of aluminum.
As far as being able to locate a Tecnacraft Aero-Foil. I've waited over six years to find one, and it certainly wasn't for lack of looking.
