#1 - not common but possible
#2 - older pocket watches often had cases made by different manufacturer than movement
I now have additional information and perhaps an explanation for the coincidence between the movement and case number.
Apparently Patek manufactured the movement for a US retailer, who made the case in the US and thus numbered it with the same number as the movement suppliedby Patek.
I have read that this was in fact a somewhat common practice in order to reduce the cost of watches given the customs duties in place back then. However, I would like to know if the experts share this view.
Furthermore, please let me know if the fact that the watch case is manufactured by the US retailer and not Patek has an adverse effect on the price of the watch and what would be such adverse effect in terms of percentage.
Thanks,
Yes, it was common for movements made by Patek to be put in cases made in the USA. I don't think that negatively impacts any value although a Patek movement in a Patek case would be particularly valuable because it's the same manufacturer.