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.
Glo is a palomino appaloosa on the pony model. Designed by Elena Christopher (aka Elaine Stone). This is the non-custom version. 250 were produced to include both the custom and non-custom versions. Unknown how many of each version was made.