the original model was built with, I believe, two or three mm thick lite ply skin. To be honest its that long now since I built the model I cant remember now. Technology has moved on leaps and bounds. There is now new Epoxy Resins which are water-based, along with light weight materials would be ideal to skin the hull over the top of lite ply or balsa.
I have built similar models recently to the Swordsman and used the water based resins which are quite good (by the way the resin is Deluxe Exe-Kote which I used). I also used the light weight woven roven matting which is the one some of the Aircraft lads and lasses use to skin the wings - its the lightest of the light of materials and it went on really well. More like a lightweight silk.