aviya
901
Yes, this is my understanding too, CR.
It's actually a dynamic I've had interest in too over the years. Lange's cases are currently produced by four different partners (FT, CO, SUG & db). For Limited Editions, I imagine Lange Uhren could specify the case numbers - but for production pieces I understand they are produced in batches. The fact that the typography of case numbers varies between cases form each of the four partners (and is uniform with the typography of other script on the case) strongly suggests to me that the partners themselves inscribe the case number.
Over many years (particularly the last 10), I've noticed pretty good "sequential regularity" of the case numbers of regular production pieces - but I've always thought that the movement numbers (which Lange, as manufacturer, wholly controls) have been even more uniform and these are therefore typically how I judge the approximate date of manufacture of a watch (well, of the movement anyway).
Per above, I've found that Limited Editions can frequently be an exception. I've also noticed that many prototype pieces of new editions of old models have very old movement numbers inside a case with a contemporary case number. Recent examples included the thinner Grand Lange 1, the Onyx Saxonia Thins and the HoneyGold Daymatic - each with 5-digit movement numbers whereas regular production is now up to 16xxxx.
An interesting post as usual CR - thank you.
Lange 1 Onyx Dial Sets - Observation (and Question)
Interesting...
I believe case serial numbers started at 110000 because Lange had made some indeterminate number of watches before then, since the 19th century.