Winston sold glass rods special order until 2000 - Sage did the same until 1990.
2001 is kind of a magic date there, since Joe Fisher closed Mound House and retired that year.
Fisher may have never catalogued S-glass rods (or identified them as such), but there's nothing keeping him from making them, especially since the process duplicates graphite - you simply use the different fibers.
It would be a question to ask
Randy Johnson, former Mound House employee.
While Grouse's photo is e-glass, the OP's looks very much like Fisher graphite finish, and is likely S-glass.