I printed this last night for my son's GoPro, so he can have a handheld camera while he is on horseback on the Mongolian steppe. He is on his way there now. Both parts printed beautifully.
One comment, the suggested screw M6x25 is a bit too long. I suggest using a 20 mm long one.
The .stp file does not open properly in Rhino. And I do not know what format the .TopPkg file is or what program would open it.