Allen Brickhaus in his stunt column in the July Flying Models discusses the Sterling S-4 1/2A kit. The Sterling S-4 was introduced as the "Space Kaydet", and is OTS legal. The name was soon changed to "Space Master". I think this was trademark or copyright issue. Barry Baxter has a wonderful set of plans which show the shapes of all the sheet sides, drawn from a complete kit. I built two of them, one with a McCoy 049 diesel, and I don't recall what the other had. As to the thin wing, there is a comment in one of the old Aeromodeller Annuals that for greatest efficiency, a wing should not have a thickness % greater than twice its chord in inches. A 5 inch chord should not have more than 10% thick airfoil, for example.