Taylors are a 1/4" nut on the truss rod. I've never owned a GSm ...are they different from all other Taylors?
BTW, Taylor had stopped shipping their guits with TR wrenches years ago. You can buy one from them, but it's simply easier to go to Sears, HDepot, etc and get yerself a 1/4" nut driver or box-end wrench.
Edward