Been working on my own "Billy the Kid" photo. I suppose it could be the same guy. The lighter grey photo the person has his head slightly rotated to his right shoulder and down and the known Billy the Kid photo he is looking more straight on with his head slightly back. I did my best to align both images. Notice both right eyes have the same opening shape as do the left eyes in both pictures. I think this could both be Billy the Kid and I think the bottom image was about 6 months before the famous tintype photo.