Closeups, drawing and painting details from the original trilogy

Not sure, but according to the style and technique this should be a Drew Struzan art work

Padme by Drew Struzan

Luke and Lea concept before the original Star Wars posters, Drew Struzan

About his career, Struzan has said: "I was poor and hungry, and illustration was the shortest path to a slice of bread, as compared to a gallery showing. I had nothing as a child. I drew on toilet paper with pencils – that was the only paper around. Probably why I love drawing so much today is because it was just all I had at the time. 

http://en.wikipedia.org/wiki/Drew_Struzan

The one and only, Drew Struzan

Drew's incredible poster art work is amazing. His style, art techniques and influence in the art world and in the movie industry is something that it will last through generations.