...isn't Jerry referring to those extra 'bushings' strapped to the sway bar, just inboard of the framerails? (I don't have his book , ...but those are what I haven't a clue what they do).
As for the sway bar bracket (those that do bolt to the frame), ...yes, those metal pieces (Feb. '69) do appear to have 'fingers' on each side, ...that it does make sense they would help keep the rubber bushing in place.