I purchased the Smart Tool digital protractor for/with my Longacre Caster Camber gauge - and a tube mount bend/notch aligner and a mag base for the Smart Tool from VanSant. Protractor can be used in all 3 setups. Works great.
http://vansantent.com/digital_levels.htm
Jim
PS, I bent some 1.5 x .250 tube 90 degrees this weekend in my Pro-Tools bender. 20 tons pushed it right around with no kinks or wrinkles.