I recently acquired this. The text looks right in terms of font and quality of printing and it is perfectly aligned with the printed SAS logo, which seems to be of a consistent colour and quality of printing. It has narrow chapter ring markers and a serial number (1684xxx) that is sufficiently early and I think dates it to a time when the Polarouter was changing to the Polerouter. Case reference is 20217-4. My slight concerns are that I've not seen one with a black dial and the dial is missing the "Polerouter" text. My instinct is that it is genuine. What do people think? This is the only photo I have currently. I can provide more photos when the watch arrives.