The last one in post two is not the unknown artist's...that one belongs to Blue Usako. That said, they are an excellent bunch, and whoever the artist is, he/she does superb work.
HDS is correct, the last picture in the second post was done by Blue Usako... however, she didn't color it, so someone took it later and did a coloring job on it. So someone does get credit for coloring, I just don't know who.
I love that series of pics of my all-time favorites. They have been floating around for a while, but still a great set. Beautiful facial expressions and positions - all very interesting. That artist has some talent.