@Pontius Navigator
Still wildly off-thread, B U T ... Within a fleet, the need is that every bit of the individual aircraft must be standard - pipes, ducts, wiring harnesses etc. Somewhere on Pprune recently I saw a mention that the Comet fuselages on the MRA4 were out by inches, while on the B777 any discrepancy's measured in thousandths. The discrepancies in internal systmes must be mind-boggling, no?
When you're knocking up, basically by hand, aircraft in a "hobbies shop", as someone said about Handley Page, to fulfil an order for say 50 aircraft at the most, you've got little incentive to invest in sophisticated jigging and you won't get the accuracy that is now needed for a production passenger jet, for which you've got orders for thousands and are delivering at a rate of, say, 10 per working week.
PS - Sorry Mods for drift ...
JP