Bob,
I'm trying to remember if you had a friend or associate that did solidworks 3d modeling for you a year or so ago. It may have been somebody else on the forum. At any rate, you could model the the skin of the tube in 3d in solidworks with the proper angles and then unroll it in the program. Print it out on a sheet of paper and you that for a template.
In 3d AutoCAD I could probably do that in ten minutes. Although I don't know if AutoCAD can unfold or unroll things. But it should be similar in solidworks.
