Hey Geoff, I'm assuming it's the bit that's supposed to be attached to the front of the OEM pannier?
If it is, it may be simpler to make it. Go to the hardware, or some such and get a small bit of 1/16th aluminium or steel plate that's the same width. Simply take a measurement from the other pannier cut it to length, then bend it to shape using a vice and a hammer, put some paint on it and bolt it back into place using stainless or gal bolts, with big enough washers on the inside of the pannier to prevent the plastic cracking.
Shouldn't be too hard, and should be easier than trying to track one down.
Mick
