Thanks Shaft109 for the tip. I'll get myself a copy.
it's was effectively down to experienced designers working literally next to the machinists with important decisions taken quickly and decisively with no interference from outside.
It does beg the question, if this is the way to get a complex project completed in a short space of time, which must be cheaper in the long run, then why don't we do this all the time? I appreciate that there is a huge difference between building a prototype and tooling up for a production run, but the basic principle is there either way.