It’s a pretty difficult proposition to secure any artwork at all for the 80s sci-fi western cartoon. But every once in a while I find a treasure like this one:
http://img195.imageshack.us/img195/5461/img1061p.jpg
This was done for the plastic thermos flask:
http://www.frontiernet.net/~phubner/GR%20Thermos%201.jpg
http://www.frontiernet.net/~phubner/GR%20Thermos%202.jpg