Theres really no way to know which line it came from, without knowing who you got it from, and what it was bred from. Sure, it may "look like" a lemon to some people, or a Graziani to some people, but theres really no way to tell. None.

As far as grade...all a matter of opinion. I personally like more blushing than high yellows. So my grade "A" may be a grade "C" to some.