I think they may have been made by several companies. I don't believe that any I have encountered had a name or label on them, but my notes indicate that the one pictured below was made by Capital(?).
They fit on Phelps Reloaders and older Star reloaders with the one piece aluminum base. They require modification in order to be used on later (post 1962) Star reloaders with the two piece aluminum base.
Not shown in the pictures, there is a long set screw that replaces the square head bolt that clamps the operating handle. Attached to that set-screw is a tab with the other end of the wire attached. When the handle is pulled, it pulls on the wire that goes around the large pulley, activating the indexer tab which pushes the cartridge from the seating station to the taper crimp station.
There is a spiral clockwork spring under the big pully which is often broken. I have seen a number of these where the owner has added a coiled spring to compensate for the broken clockwork spring.
These indexers cause the same wear to the steel base as a Brewster or Hoyer Indexer, but in a different location.
Bruce Williams
