Assume if your talking to Derek is a new build, so all new parts. It may be to late for my first comment, but here goes anyway, If you have a removable steering wheel, and intend for Caterham to do the IVA, don't bother with the top steering column bush. It will be removed and refitted during the process, so save the effort. When you do put it in, make sure the plastic insert is the correct way round. If its incorrect it will push into the column tube as you fit the upper column. Don't connect the lower column to the UJ until you have the upper and lower columns in place (not clamped), in fact don't have the UJ on the rack either for that extra bit of space. Lube the columns inside on upper and outside on lower, and wiggle them as they slide. My S3 had a little unused fixing hole and tang that just touched the lower column (in the pedal box), it was spotted during IVA and a simple bend of the unused fixing point solved the problem, but maybe this is causing your alignment problem? Finally you could always remove the grommets from the cheese wedge to get that bit more wiggle room, but they may be a cow to refit.