My 56 cab was damaged some time in its past, in storage. I was told the building collapsed and a beam landed across the cab roof, creased it almost from drip rail to drip rail. Today I just tried laying on the seat and pushing up against the roof, little gain that way. So I'm thinking, take out the seat, lay 3/4" plywood across the cab floor, bottle jack on that to a 4x4 post under a 2x6 agaist the cab roof, and slowly jack it up to hopefully push most of the dent up. But any expertise about where to push first to make it better rather than worse?