I hope the photos load, otherwise this may just be a rambling entry.
About six years ago I moved my top box forward to get a better center of gravity, better air flow, and use it as my backrest. It turned out to be a little high and was actually uncomfortable for where the pad hit my back. I moved it back about three inches and built a backrest that is adjustable and a little lower for better lumbar support. The backrest attaches to the frame supporting the top box and everything can be removed in about two minutes to have room for a passenger with the top box in its original position. The top box carries a Harbor Freight waterproof box on a plastic platform made from a cutting board from WalMart. I milled holes for bungee attachments and for the waterproof box with some spools on the box bottom and a 1/4" bolt to keep it in place. At one time I used a tank bag for the misc. items (camera, glasses, SPF, etc.) but it was a bit of a hassle every time I left the bike alone while it was parked. The plastic holder on the tank for the maps covers a larger map area than the bag did and it is less of a temptation for the snatch-and-run crook. The top box platform attachment mirrors the original placement grooves and holes so it clamps in place just like it was made to do. All of the framing was made with pieces of aluminum that I had found in second hand stores and when Sears was closing its hardware store. "Someday" I'll go back and clean up the rough assembly.
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