wow thank you for all the help. This is a great community
Three suggestions once you get locks with a key.
1. Make sure you use a little blue loctite on the two tiny screws that hold each lock in place; you can read many posts about the problems you may have if you don't.
2. Always push down on the lid when you lock/unlock the box. This will make your life easier and help prevent breakage of the plastic locking hook (for which there is no replacement part).
3. Consider asking a locksmith to cut a new box key on a ILCO X254 blank. It's shorter and stronger and will work better for the boxes. Have the smith line it up and cut it like he would a normal copy and don't worry about the extra length of the master that is not copied, the locks don't need that. This may not be needed if you follow #2, but too many have bent their keys in pannier locks by forcing them to turn without taking the pressure off by pushing down the top. It wouldn't necessarily be a problem for you since you will already have a different key than the rest of your bike uses, but there have been those with original locks that use their bike's ignition ignition/gas cap key and have been stuck and unable to start their bikes with a bent key after using it forcefully in the pannier/top box locks.
Just a few thoughts. Good luck. Hope you were able to grab those eBay locks with the key.