Question on ofVideoDevice + identify webcams of same model

i am looking in to this right now too.
in the ofxUVC addon in UVCCameraControl.m they are able to get the locationID

(*deviceInterface)->GetLocationID(deviceInterface, &currentLocationID);

these are numbers that look like this:
3145728
1076887552
1048576
1077936128

in ofxUVC you can set the camera via it's location with initWithLocationID

all this to say there should be a way to identify and select a camera according to its locationID.