What I have done is pulled one of the locks off the pannier and opened up the mechanism to see how it operates. It is a very simple design with basically one moving part and a spring. I was fortunate enough to have a key that went into the lock, but would not turn. With the lock apart I was able to see where the key needed to be cut in order to operate correctly. I cut my key by hand, and then file finished it for smooth operation. Works a treat, and the best thing is that the key fits both sides, and would suit any lock the same due to it's simple design.
The photos show the old original rivets, and then the replacement stainless bolts and nylock nuts. I did not replace the rivets on the lid as I didn't need to, but the way the lid closes over the lower part of the pannier makes fitting nylock nuts (or any nut) impossible without fouling on the seal.
