Is this practical?

[Arnold Schnitzer]

Surprising. I doubt you have a bass bar issue. I don't think a sprung bass bar would exert enough force to blow open a rib. I think perhaps the back has dried out and tried to shrink, resulting in the edges pulling away from the rib assembly. Have you had open back seams? If so, was the gap wide? When you say more wood was laminated to the ribs, do you mean narrow strips or full-width? With the grain or across it?