To be honest, I tend to dislike udev, and about the only thing I do with them on a regular basis is delete lines in the persistent-net file so I can reclaim eth0...
UUID and labels might be better options, but udev should work too. (Assuming you can get the rules figured out). I tend to dislike the label and UUID options, so I would probably try the udev method if I needed to do this. However, if I couldn't get it working within 30 minutes, I would probably just fall back to UUID. Two days sounds excessive, but given how infrequently it comes up and other ways around the problem, I can see it taking that long... Given this specific problem, and the removable backup device changing, the putting the label in the fstab method probably makes the most sense.
