Gooseneck LD(Long Distance Touring) stems were generally on threaded forks with a brazed stubby on the end im Album #ll Proto DIA Cunningham O Potts (MountainTrans & Team Trailmaster Archive)🔧🔗

These stubs were used early on by Wtb and charlie continued to make use of these while WTB then went on with their conical press fit system which had a special adapter for pinchbolt dropbar stems.
(mainly to accomodate oversied tubing..)

Of course you could have drllled the dop of the bend tubing but that wasnt something they did usually (a rare example has been spotted anyway..)