You are probably correct. One has to wonder what became of the 10x36 lathe, though. Never mind the mica under cutter. Which few would have any work for.
Be that as it may, there is a photo in the stack that shows the blade holding arbor. Unfortunately, it is sans one of the slitting saw blades which are all of the same diameter but different thicknesses to cater to the various widths (thicknesses) that armature commutators came with. Back in the day, Atlas sold a replacement blade kit which came with a variety of different thickness blades, all of the same diameter.