It sits beyond the truss rod cover and it located 3/4 of the way between the 6/1 string tuners and the 5/2 tuners. In fact, it may well be in that case that it holds the 4th and 3rd strings. Odd devic ...
I'm totally at a loss with this one and I haven't seen Guthrie as of late so I can't ask him, but I am wondering if anybody knows what the device is that he has on the strings behind the nut on his ol ...