I have this 1883 V nickel with what looks like a Lamination Error . I thought earlier it was a stain but there are two cracked lines from the edge in through Lady Liberty's head . Comments and gratuity welcome .
Is it a "crack" or a stain? Hard to tell from your photos. Because it isn't affecting the star, I'd say it is a stain unless you can verify there are actual cracks in the surface.
I think it should grade higher but if you don't look closely it does appear to be a stain. I don't think it a stain, I think it's the color of the coin due to the lamination.