I agree with everything that has been said, except that there are no descent air rotor retracts out there either. The TF Corsair when finished is about
9-12 pounds, depending on the finish and mods. The rotor Robart retracts recommended for that model are unreliable and prone to failure at this weight. I have seen plenty of pilots complain about the Robart gear and I've seen how poorly they are designed and how easily they get damaged. There are other rotor retract systems out there as well, but I have not heard much positive comments on these either. The one retract that probably would be OK is no longer made. They were the called Rohm Airs and they actually were quite rugged and reliable. Unfortunately, they are hard to fine. Anyway, good luck.
Don