On Apple's spec page I'm seeing "CDMA model A1429" and "GSM model A1429" (vs "GSM model A1428" for AT&T). I'll agree that the first two are different model names, but they look like the same model number ("A1429") to me. That's why I suspect the differences between the two devices are smaller than we might ordinarily expect (possibly including smaller identification differences).
Do the two A1429 models actually show up differently in this sort of breakdown (presumably with "GSM model A1429" as iPhone 5,3)?
However, there really are three. (edit: Or not. I've been asking around and there are mixed opinions. We generally care deeply, being those crazy jailbreak people, but we haven't gotten to that stage on the 5 yet.)
I can then say that there are only two device names: iPhone5,1 and iPhone5,2, so yeah: normal ways to differentiate them won't work, you'd have to do something special.
Do the two A1429 models actually show up differently in this sort of breakdown (presumably with "GSM model A1429" as iPhone 5,3)?