There is no hard rules on how many millimetres this way, or that way. Fact is that I don't even care. That is not the important part. The important part is that the rivet sits in the top corner relative to your own build, and that it looks clean and neat. The screen used suits used cap rivets that become flat when hammered down, but we will also allow the domed split rivets. See our reference photos we keep on the site for this matter: http://www.whitearmo...eferenceGallery
Like this picture which is pretty good hints that the rivet is really in the corner, very few mm from each edge.