Does anyone know at what point in time aluminum T masts may have changed to a modern, pre-bend, style of diamond spreader set-up? Any distinguishing visible differences? Like said, I not sure even the current owner knows exactly what vintage this boat is.

And now I'm confused by your statements on luff curve. We had an TheMightyHobie18 with the "sideways" bend mast. Honestly I never paid attention to that sail's luff curve. Conversely, the mast prebend and luff curve of the H20 is very prominent. Without dragging out my copy of "Cat sailing for the 90's", doesn't the sideways bend produce draft? Seems like a sail with less luff curve will work on the old school mast. <img src="http://www.catsailor.com/forums/images/graemlins/confused.gif" alt="" />