Bought a rivet gun (it is single shot, no ID required), used it, then found the directions on the inside of the folded paper backing.
Used one, eighth inch aluminum rivet in the middle of the edge of the two, equal sized, stacked sheets, so I can spin one sheet horizontally to spread the fan, then spin it back for more compact storage. The doubled edge is less sharp than a single edge.
As usual, the tools cost about the price of a nice Ti wind screen of about the same weight, so I now have the pride of owning my own dirtbag version that works almost as well as a professional one. I'm looking forward to wasting money on a single use tool for my next DIY project, maybe a laminator for bonding mylar layers into poorly made cuben. I'm only limited by my imagination and my life savings.