Yep, former coat hanger and very similar to yours but not a total copycat
Dlofx, the stir arm is connected pretty much the same way as the stock arm. I did cut a copper washer and fold down a couple of teeth that hold the arm better. Coat hanger wire is a little smaller than the stock wire, so the new arm was floppy. Also a piece of the plastic shaft eventually broke off and the teeth were a necessity at that point. <edit> when I first read your post I thought it said "connect" and when I looked again I realized you said "concoct"... Creating it was fairly simple. Step 1, channel your inner Peter and find a coat hanger. Cut and straighten coat hanger and remove the paint. Start in the middle and make a bend where the screw will wrap around it - use the stock arm as a guide and slowly work out from the center. Bend and test fit as you go. It is tedious, do it when you're bored and have time to kill.
The aluminum shaft sounds great - I didn't know they were still available.
Oh, and the Ethiopian Yirg I just roasted... test batch of 200 grams, 1C at 8 minutes and got quiet at 11, first snap of 2C at 13, pulled beans at 13:30