I retired from my work and left tools and aluminum parts and pieces at our family shop . A big mistake that was and I must have been in a state of serious depression . This was a one of a kind 1/4 inch thick elliptical 15 1/2 inch diameter hull with a 5/8 inch thick plate 1/4 inch captured o ring . It truly was a industrial beast and the aluminum sphere to make the shape came from rocket ship parts . The owner at Norton Sales said 4 of those helium spheres cost 1 million dollars . Sounds like a crock of B. S. and the wife is complaining go eat your diner , will finish rest of the story soon .