You ordered rail covers?! That's a special offense where the FBI will actually leave the US, and come kick in your door here in Canada. They'd normally send in DEVGRU, but ever since the whole Bin Laden thing, the whole spec-ops community feels they're above retrieving rail covers.
In seriousness, I can see why you might be concerned about the legality of importing something if the manufacturer themselves won't export it, while some hole-in-the-wall company without a team of lawyers would be willing to send it, but rail covers are fine. =)