Great find Allen a long time back I posted about how I used a coaster brake hub on a rear disk brake conversion for my Simplex style build and some of the replies ranged from "it won't work" to "internal hub changes required". Quite a few miles ridden now and no problems, works fine. Because I knew how a coaster brake functions I was able to utilize "simply" what I had to what was required and no internal hub changes necessary. Coasting efficiency was as is still good and the same. I did however uninstall the brake arm, lol.
Rick C.