Again, Northwing, you're talking about a forty-plus year-old aircraft. Contrast that with the current Canabeer CRJ or Boring 737-NG where 100s of aircraft are built on a true production line. On a recent visit to Renton, we were informed that the standard installation provision for the HUD (either of two flavours) was done in Wichita and then did not need any realignment when the system was finally fitted in Renton i.e. repeatable measurements to optical standards!