Some wheel alignment shops (like the one where I grew up) had equipment to bend and/or twist straight axles to get the caster and camber right. Caster was usually adjusted by shimming both sides to tilt the axle, but one with a twist already in it might only need a shim on one side. Have a good alignment shop check it to see what the variation is side to side. The oldtime correction for road crown to make the vehicle track straight was to put 1/2 degree less positive caster on the driver's side.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!