I'm in a training class today, or I'd measure it right now, I'll try to do this when I get home tonight (made a note in my Pilot

), that is, if Yvan hasn't already posted them in the meantime.
The lid does stay up on it's own pretty well, when the hinge screws are tensioned properly (see the note in the review about these screws & white glue for more details).
The extra width is necessary for structural strength, 'cause wood requires more thickness for the same amount of strength compared to metal or plastic.
The box in Yvan's avatar is indeed the same one, the differences in appearance are most likely due to differences in lighting, camera and the the photographer himself. If you like Yvan's avatar better, then clearly
he's the better photographer.