I just leave the screw in it cause sometimes I use a Mustang pillion. Accidentally knocked that c-clip off the stock plug that the rear seat screws down to one time. It was a pain in the *** to get my arm up between the fender and the tire, hold that plug in place, and get that clip back on.
Get a long zip tie and thread it through the plug. It is easy to pull the zip tie up through the fender hole without having to put your arm up the fender. After you clip the insert in place, just let the zip tie fall out. Easy Peazy.
Just get a piece of wire a foot or two long, and twist a washer on one end. Drop the fender nut over the wire, stick the wire up through the hole, and pull the nut up after it. Pull it up through the hole and put the clip on. Done. Let go of the wire and it falls right back down on the ground.
Ha. I just read your post. I just posted basically the same thing, but you beat me to it.
Yep - fitted the 762 to the bike tonight. It doesn't go quite flush down to the fender. I guess it sits about 2mm off due to the clip which keeps the captive nut in place. Not very noticeable however and looks fairly tidy. Result!