Making one mold for a universal,trimable,convenient prop may be OK for sport applications but trying to get efficient,high thrust props for competition is the direction we're heading.After spending all that time with Billy talking the what,why,and how about props it would be an insult to him if I did not try to build the better mousetrap.I made reuseable mold forms and molds are easy enough to make.If it takes a half dozen molds to finally get "That magic prop" it will be worth the effort.Bill Werwage didn't win 3 world championships settling for convenient.Testing,testing,and more testing is the key.I know I'll never fly like him but I will use all the knowledge he bestowed me to make him proud.