It starts to become a trend, Rolex plus a fountain pen are the best matches. Previously I showed a possibility to match the Montegrappa Rainbow fountain pen with your watch, a Rolex Rainbow. This would give a very interesting vibe I guess, matching the belt with the shoes seems very outdated. :)
Another Rolex and another cool fountain pen. The TWSBI Diamond red-blue (Pepsi) would go really well with the Rolex Explorer GMT Pepsi bezel. I would choose the white dial version of the Rolex for a better match.
I could have gone with any of the beautiful watches available with pepsi bezel like the Seiko, Orient, Tudor, or other. But I think when you think pepsi bezel you immediately imagine a Rolex.