Water forming is next step. Make a plug out of two part epoxy, sand and shape into shape, and then lay you wet pieces over it. When they dry, you will have you shape, and see where you need to cut and shape a final shape, to take the shape, and have your perfect bell, it's a progressive procedure, one I first did at 8 years old using the many spoons my mother had, trying to get the shape my "Uncle Martin"s" graceful spaceship. I got really close, close enough to glue and sand it, then spray paint it Silver, and I played for it for a very long time. I think it may have been stolen, as one day, it was just gone. I used the same technique to make fenders for cars. I soon learned that you did not want to make the parts exact, just let the piece dry on the spoon, and cut out the shape. Many years later, when I saw how Mahogany stripped yachts were built, using a multi contoured buck, I was able to modify my methodology. Glue the inside surface when you remove it, and you then end up with a very strong parts, made from crisscrossed strips of paper added on the back side, with a hard glue core. I filled with a skim of glue, and sanded to shape. People must expect to have to fabricate more to get the models they wish. Not everything can be printed out.