There's no such thing as a Guild George Strait Signature guitar.
It is a regular D-4 with a mahogany top and a hand-rub finish from 1998 that was signed by George Strait.
I saw that one out there last year. As I recall, it finally sold for around 600.00. George Strait is a D100 guy; can't see him owning a D-4, but he may have signed it for someone. Got a feeling that one will be there for a while at that price...