Hi Bill, nice presentation.
Some nitpicking about the Marine Chronometer f2.4MHz:
The prototype was actually certified as such by the Neuchatel Observatory after 63 days of testing. Its average daily drift was less than 2/1000 second per day. or 0.73 second per year. (Marco Richon)
The movement physical dimensions also had to conform with the Neuchatel Observatory standards for a marine chronometer worn on the wrist. (Marco Richon)
I read that the decision to send the commercial MC watches to the Besancon observatory for certification was taken because the Swiss observatories were operating at full capacity at the time.
As for differences in price between MC and non MC, Most of it was probably due to the cost of the stringent marine chronometer certification and also the extra manpower required to regulate the movements, before the tests took place.
According to my certificate, it looks like the temperature variation criteria was the hardest to meet. (0.022 for a max allowed of 0.070)
Cheers,
Thierry