Shimming is the way to go. Saunders enlargers were always marketed as perfect out of the box so they have no adjustments, but I don't know what perfect they were talking about. It sure wasn't my perfect. Shimming solved the issues.
I like ic-racer's baseboard. that sure is a lot simpler than shimming the column! An elegant solution. That is a perfect solution for a wall mounted enlarger as well.