First of all, there is no such thing as a camera where everything is always in perfect alignment. You
can't take anything for granted, esp with used equipment. Second, well made equipment will have a
provision to correct these kinds of problems. Even my Sinar Norma camera made half a century ago
can be fine-tuned to regain its original settings, but the components are in good shape without much
actual wear or slop. Third, to readjust things correctly you need proper machinist-quality levels and
squares etc - don't expect to go to Home Cheapo and purchase any level worthy of the task. High
end metal monorails or technical cameras made from die-castings are likley to be the best bet for
long-term precision; but some expensive wooden cameras like Ebony can be surprisingly good. Wood
can warp if its not kept sealed, of course. Used monorails, esp Sinar, seem to be a bargain at the
moment, but beware of patched-together ones from worn or mismatched components.