I just picked up a 2007 F650GSA with 9700mi on it. The PO was not kind to it, or at least didn't put any effort into fixing damages bits. It has factory side cases. One of the mounting tabs on the left case is broken and the lower bar that the right case hooks on seems to be bent down a bit meaning that the right case is very loose & not secure. Any suggestions on where to find a replacement left side case for the cheapest price? Does anyone make aftermarket cases that mount on the factory racks? Has anyone tried bending the rack back into shape and is it secure after that?
Try eBay. Lots of cases on there from time to time. As for other bags that mount directly on the BMW racks, I'm not aware of any. If the mount is bent, you really have nothing to lose by trying to bend it back. I'd take it off the bike and use a large vise to hold it. Maybe use a piece of pipe to increase your leverage. You might want to apply some heat (from a propane torch) before trying to bend it. Pictures often help bring additional suggestions.
Factory cases are a modular design. Serveral years ago a tab broke and i bought a factory replacement of the bottom piece with both tabs and re assembled the case good as new.
When I was using the BMW Vario's the lugs broke following falls, repaired with alloy angle, see the info on the web site