[Milsurplus] TBY-4 hammified antenna connector ?

[Hubert Miller]

The hammified one I have, has the older 2-antenna post form, not the rotating ceramic insulator on Andy's -4.
So the one I pictured has to be earlier. Does anyone know which suffix went to the ceramic insulator ? 
Not only the angle-adjustable rotating insulator, but these later ones incorporated a large spring in one antenna
section. Seems they learned something from experience.
-Hue