While not a huge number of people have watched the show, it has had some effect on fashion, particularly men's fashion. Several months ago I walked past the Manhattan Brooks Brothers' windows, which had a Mad Men theme, with the male mannequins wearing slim suits with slim lapels and slim ties. You're seeing this more and more with Hollywood actors as well, especially the slim ties. What goes around, comes around, right?
It's happening in women's wear too. My wife was looking at some dresses on line that were billed as "Mad Men dresses", meaning they had vintage lines and resembled those worn by the women on the show.
As to your other question about 60s ad execs wearing Timexes to pitch ad ideas, if the show is true at all, I'd say absolutely! Timex might have even sent them some samples to help them know the product better and come up with a strategy.