I don't currently have any more alum. plate to work with. I'll check to see if I can get any more at work. The backrest just bolts to the support brackets. Remove 4 bolts to disassemble. The luggage rack uses the same bolts so you have to replace with some 3/8 bolts.
I got mine from Scootworks. They also sell the Wompus brand mounting racks. The rack is custom made for each make & model bike, but the trunk mounting holes must be drilled, as any make of trunk can be used on the Wompus rack. My tourpack came in black gel coat and I had it painted gloss black. I later had it pinstriped to match my saddlebags. The backrest with armrests was also from Scootworks and is made by Mustang seats. The luggage rack on top of the tour pack lid is made by Kuryakin, also ordered from Scootworks.