I also could not get the links to work, but it sounds like a royal 40s or shoulder wing. Royals attempt at an intermediate trainer. A good safe balance point is the main spar or about 25-30% back from the leading edge. A 10x6 or 11x5 will work for flight, for break-in I would use the 10x6. I don't think they have made those aircraft since the mid to late 90's. I have the trainer version and other than a slow roll rate it is a good flying and well built trainer, I am just finishing a total refurb. due to hanger rash. On a side note most were covered in a non iron on covering(much like a sticker, you will notice the design has plastic tips to avoid compound curves.) so repair can be difficult. This is all assuming it was made around the early 90's. It should be white with red and blue trim and black plastic tips on the wing, horizontals, and vertical tail.