are you sure you can't align the lens stage? I don't use a B22, but have a couple of old D2s and you can align the whole carriage part in addition to the neg stage. The part that holds the lens boards, is aligned by rotating these plastic wheels that run up & down the column-if you loosen the screws that hold those in place, they're actually offset, so if you turn the wheels around, you can adjust the carriage from front to back. You align that part, then you do the negative stage. If you need to adjust laterally, there's a similar provision...