Nice watch Jarl, I'm starting to like these a lot too. Kinda wish I'd been around to bid on the gold one that was up recently, but I'm not sure I'd have kept it.

The early Carreras only had a serial number engraved on the case too, no model reference number - looks like this became widespread practice throughout the range at some point in the late 60s.

Can really see the case beginning to evolve on this one.