Are these the bags you have?

You need these to mount them on....


I used and modified a set of them to mount my Mustang hard bags with.

Unfortunately for you, they're made of unobtainium and are no longer available. If you find them, be prepared to pay top dollar for them. Your best bet would be to post a wanted ad in the VRCC's classifieds, check eBay or Craigslist.
Good luck.