I understand that the balance cock (or equivalent) of every Lange watch bears the individualized engraving of the watchmaker who put it together. Indeed, I understand that these engravings enable watchmakers at Lange to know at a glance exactly which of their colleagues made a particular watch. Here's a photo of the engraving on my first-generation 1815 chrono. It doesn't look at all like the unitary baroque pattern on my Lange 1 or most other engravings I've seen in photos of Lange movements. Although it has the usual curls on part of its surface, the portion closest to the balance wheel contains severe cross-hashes and at least one initial (an "N"). My quick survey of web images for Lange engravings shows this "N" and cross-hash arrangement only on a few other watches, and they're all 1815 chronos (although most 1815 chronos don't have it). This is obviously just idle curiosity, but does anyone else have this type of engraving or know the back story to it?