Without looking through my collection, I'm going to guess that the long grey tag started in FW10, or around then.
Regarding the clasp, I have a pair from SS07 which has a different clasp than several of my jeans from FW07, both of which are different from the clasps used now. I even discussed this with the guys at one of the boutiques recently, when they were trying to authenticate an older pair that a customer had brought in.
I don't see anything about your pair to be worried that they aren't authentic. You just have to get them tapered a bit.