I tried googling them to find out offsets and i'm getting arount +30 for front 16x7s and +35 for rear 16x8s. But i'm not entirely sure. Would it say on the rim? I pm'd dom to find out if he knows.
As for the legality of them, unless they are actually poking out, a cop doing an inspection isn't going to pick up on them anyway. So it's just a case of what they don't know don't hurt them...