Until the end of 1982, G&L used a neck with a so-called skunk stripe. A channel of the right shape would be routed on the back of the neck in which the single-action truss rod was inserted. The channel would then be closed with a strip of wood, typically mahogany, which would give it its appearance. How does the truss rod work? “Single-action” means a single rod is used which is anchored on one end of the neck with a truss rod nut at the other end, the headstock in case of a G&L, usually with 1 or more washers underneath. By turning this nut clockwise, one shortens the distance between the 2 ends and the middle of the neck will move upward due to the compression, decreasing relief. When turning the nut anti-clockwise, the neck is not pushed the other way. Rather, by relieving the tension in the rod, the strings will pull the headstock up hence increasing relief. Below are a couple of examples. of instruments with the skunk-stripe appearance. The very early instruments, including the F-100 Series I and L-2000E bass below, both from 1981, had a chromed neck plate. Later on, this neck plate was replaced with a black powder-coated version as seen on this 1981 G-200 w/”rain cloud” control panel below. The headstock on this G-200 also exhibits the hook or “teat”, now so typical for any G&L. Although headstock width have varied and are different for certain models of a certain era, the basic layout is covered in US Pat. Des. 270,544.