First of all, are you stating it only moves inline with the barrel? There is no other rotational plane that it moves in. To the best of my knowledge, the Kragicon stacking swivel has no flat portion of the circle. On the other hand a 1917 does have a flat portion. Just a guess, but maybe it was replaced in error. Again just inline movement no rotation. The lower band pin is blued and .1" in dia.x 1.056" in length with rounded ends. At least according to Joe Poyers Krag book. If you can't find anything maybe a finishing nail cut and ends blacked might work. John