Depending on the age of the racket and the final result desired, it's possible to 'straighten' a warped piece(s) of wood. Wood is shaped by steaming for many purposes. Dunking a racket in water isn't the most direct approach; but, it might serve(!) the purpose of helping flatten a curved racket. For display purposes, an acceptable result might be achieved by steaming or dunking the racket, bracing it into its 'original' shape and leaving it for an extended period. A metal 'Zephyr' press would be preferable to a wood press...the wood press itself might warp or break. I would use a greater amount of weight carefully applied with some padding, securing the racket in the desired shape(or moving in that direction, slowly).
There's no guarantee of the results and I wouldn't try to return a 'playing' racket to its original shape and expect it to hold up to actual play. I would try to 'restore' a warped vintage racket to be used for display purposes. I would expect most rackets made 50+ years ago to be more 'amenable' to re-shaping by the methods discussed.
Hey, c'mon, just try dunking a warped woodie in water with a press on! It works! Then string it up. At least there's no need for new grommets!
McEnroe has said that he sometimes warms up with a woodie.