Well, I'm guessing that the extrusion process for the original bar stock left residual stresses in the material. When a long row of holes was drilled on one side, it started relieving those residual stresses. Plastics are well known to "creep" under long term stress. Hot storage would have made the creep progress faster as creep has a temperature dependency.
As the body tube has bent, it may or may not have caused either binding or looseness in the keywork, depending on the axis of the bend. The posts are screwed into the plastic, so there are residual stresses around their bases too, and I imagine them almost as floating in the very very viscous material of the body.
Frankly, if it's not causing mechanical problems, I'd leave it alone and consider it a curiosity.
As the body tube has bent, it may or may not have caused either binding or looseness in the keywork, depending on the axis of the bend. The posts are screwed into the plastic, so there are residual stresses around their bases too, and I imagine them almost as floating in the very very viscous material of the body.
Frankly, if it's not causing mechanical problems, I'd leave it alone and consider it a curiosity.