I mounted some old samsonite small suitcases (metal and plastic). I ran longer bolts through the grab rails. To those bolts (using spacers to hold it away from the grab rails) I attached some lengths of bar stock to make a small brace. I bolted the suitcases to the brace. They're removeable (4 bolts) but not quick-detachable. They hold a ton and the weight sits low on the bike.
MF Battery, Iridium Plugs, RR relocated, Voltmeter, 170/80/15 Kenda Kruz rear tire, DIY Samsonite hard bags, DIY shaved seat with Beaded seat pad ('cause that's how I roll) and the dreaded STATOR CHANGE.
Shining Black Bess '86 VN750, retired for parts after a fried stator and being knocked (kee-runch) in her parking spot.