Early-A Convertible Chassis Reinforcement
Weld in a set of frame connectors, made from 2x4 inch rectangle steel tubing 120 wall, make a cardboard template of the contour of your floor and transfer it to the rectangular tube, after a lot of grinding, and welding you won't have any problems with keeping things straight and strong. Xv and us cartool sells them but I don't think they have them for early a bodys.