What you describe is so strange. I looked at the photos again and it's hard to say if the bed is hinged at midpoint. What is even more strange is that the cylinders would have to pull rather than push to lift the body. And as far as balance is concerned the winch cyliders and headache rack are ahead of the hinge point so that means it is heavier up front. Maybe they figured on driving the tractors slowly back and just letting the body sort of ease down with those cylinders acting like shock absorbers. BTW, is there a body manufacturer tag on the bed?
Well you learn something everyday but this one is sort of out there. Anyway it is a really neat truck and I hope you do restore it to original Oliver dealership detail.