I have a 1985 30'' Carl Schumacher designed ULDB. I am trying to find parts for the mast and boom, regarding changing halyards and increasing the outhaul purchase, but cannot locate a source. A plate on the aluminum tapered mast says "Sparcraft Blue Label, Charlotte, NC, and a second plate says "Isomat". I had thought that Sparcraft was a well known brand; however, the only one I can find is in France. Does anyone know the background for these present or former suppliers and a possible source of parts? Thank You.