While I wait to find a replacement, I attempted to temporarily fix a broken rear turn signal.
Turns out that the base of the signal is rubber with a metal threaded boss insert. The rest of the rubber base has a slightly larger than 1/4" hole running through it. At first I was just going to find a big pan head screw to thread into the base, but that would have required enlarging the mounting hole in the tray which I did not want to do. It occurred to me that some kind of insert might work so I headed off to the hardware store. Found that a #10-12 plastic anchor was a tight fit in the hole and the #10 screw with it a good fit in the tray mounting hole. I did however, have to drill out the threads in the base insert...it can be pressed out and has hex features so it can be clamped in a vise for drilling (I used a 1/4" drill). When completely assembled, it looks nearly normal, but it will not flex out of the way if hit. So...anybody got a spare left rear signal?