This is Guild's version of the classic Bigsby B-6. It's been in use since 1961 and it was the standard Bigsby on the Starfire models, the Duane Eddy-400, the Studio Models and many others. Note that the post-1967 double cutaway Starfire models (with the neck joint at the 18th fret) were outfitted with a Guild B-9 Bigsby.
There are a lot of people looking for the Guild B-2 Bigsby and I currently don't have any in stock. I'm always trying to find some though, so check back here often.