Jon,
Fascinating stuff. Doubly interesting is that the American standards of today for many things Imperial are more accurate than the adulterated ones now outlawed in Britain. I use and like like both systems but if not,(according to a learned friend), for a deliberately introduced error of around 0.004995" in a meter when the Metric system was finalized swapping between the systems would be easy. This would apparently make the Metric system easy to ratio to all the ancient measurement systems,(which can be done with the Imperial system), and a lot of archaeology that is puzzled over by those using Metric would make sense.