Since you handled it I have to think you are correct about the 45mm size. However, the Zenith site shows it to be 42mm just like the other two current 410 variations. I have the steel/silver dial version on my short list but I started thinking about the blue one when I read about it...until you said it was 45mm. If it is indeed 45mm I guess it would simplify my choice.
Thanks for the great pictures. Yours are the first I've seen where the blue strap is actually shown as dark blue, which I prefer, compared to a medium blue seen on the Zenith site. Did you find it to be a dark blue in person?
thanks,
Fads