As I don't want to start a discussion with Ron (who (I think, according to the many posts) is a real expert, I just want to give some facts why I think my MBK is a model 7 :
Except for the rear suspension and the slightly different fork, it looks exactly like the in hte picture gallery
The Identification plate reads : Model 7/25 (which I think means model 7 / 25 Km/h)
I also have a Motobecane Mobylette 50v which looks different (fueltank / speedometer / headlight)
Maybe this one is newer (or older), so they might have added rear suspensions.
PS about the bolt : I didn't knew about the rubber inside, to I decided to leave it in. Because I want to protect it for the sandblasting, I taped it thoroughly.