I bought one of these almost seven years ago and have been very happy with it. I mounted it to the metal strip on my Memphis Fats and it has been perfect. The only issue was finding a flush mount screw that looked like the other screws from the outside.
https://www.ebay.com/itm/-/112719472178?fromMakeTrack=trueAll the other mounts are either ugly or complex. This is simple and elegant and puts the GPS right where I want it.