The Signature Series was a program where an artist would design a model, and then the Stone Co employees painted them. Each model had a stylized sticker of the artists' signature, and came with a Certificate of Ownership.
Shotgun Sally is a dapple buckskin ISH designed by Carrie Keller. I believe this run was all matte. This was a run of 250 models consisting of Shotgun Sally and Ima Tommy Gun.