The whole thing is stupid since you can legally transport it unloaded and NOT IN A BOX AT ALL if carried out in the open, not that I advocate it for obvious reasons.
Though I guess there have been some cases ending otherwise, I think the wording is clear that the ammo can, in fact, be with the gun as long as the gun is not loaded. Oh, the evils of case law
Either way, play it safe and keep them separated by a lock just in case you wind up on the stupid end of a copper or JOP someday.