Originally the Comet gearbox had no adjuster at the cable entry, just a plain slotted abutment, G94/1. Most gearboxes, however do have a 3/8" C.E.I. thread there. Panther gearboxes have an adjuster there because it is easier to get at than the Comet. I sometimes do fit an adjuster, though it is a bugger to reach, but fitting an adjuster in the cable about 15 inches back from the gearbox entry is an easier wheeze for adjustment. The original cables had an adjuster right where it scrapes paint off the top fork link. Not the best plan. I've not noticed a taper in the fork end, but these old eyes aren't what they used to be; they used to be my knees.