I just purchased a zeith 10s160 speaker and acoustical cone from ebay. It only has 2 mounting holes(which have grommets) for only 2 brass rods. I have another 10s160 that has 4 holes (2 with grommets, 2 without) and has 4 brass rods. Did Zenith change the design later in the year from 2 holes to 4 holes?

Hi.
My 10S153 has four holes in the cone too. I suspect that it may have been more a matter of the suppliers providing the cone, and/or production runs of the speakers, the mounting boards, etc. Running production changes were common, and on something that inconsequential to the external appearance or performance, probably was not cataloged.

: I just purchased a zeith 10s160 speaker and acoustical cone from ebay. It only has 2 mounting holes(which have grommets) for only 2 brass rods. I have another 10s160 that has 4 holes (2 with grommets, 2 without) and has 4 brass rods. Did Zenith change the design later in the year from 2 holes to 4 holes?