In the meantime, there’s some evidence that Worldwide distributors hated the inconsistent and infrequently illogical numbering devices of their Swiss overlords. Even though the crystals to the 160xx technology of Datejust watches are still produced from acrylic, the sloped "pie pan" fashion dial from the preceding era is absent, and https://www.watchesworld.com/a-history-of-watch-reference-numbers/