If you want to rebuild a British glider you'd be better going to look for the remains of a Hamilcar, as the metal used on it was mostly Stainless Steel and survives very well, probably reusable. Of course if you seriously want a Horsa or Hamilcar you will also need a lot of wood, and I mean a LOT of wood. The Horsa was the size of a WWII heavy bomber and with a wingspan of 110ft the Hamilcar was bigger.