In reply to Tom.

Yes, although it is equally possible that Rolex also used Aegler for the design and development of its movements (based on Rolex-supplied rough specs/parameters), and then had an exclusive arrangement with Aegler where any of the Rolex designs and technology could not be used in any other watches. This is a rather common practice for brands that are part of a larger parent group, where one of the other brands is exclusively a movement manufacturer (for example, how ETA is part of the greater Swatch Group).