No, not rollers. Those are the same type (but smaller) adjustable pieces like on the 6 string Hagström bridge:
The above picture is not from a Guild but a Hagström guitar. But it shows how the pieces are mounted.
The Starfire IV for instance used that type:
Hagström even had this 8 string version, and here you see that the 8 individual saddle pieces are very narrow compared to the 6 string version:
Ralf