TJoy-M1: Joy-con Grip for Toughpad FZ-M1
I know nobody needs this thing, just made it for fun.
(But my FZ-M1 M5-6y57 can actually run Devil May Cry 4 at 60FPS! Isn't that cool?)
In addition to the screws and nuts mentioned in the installation guide, you also need 2 springs, size 0.4x3x5.