Is this for a mill or your Myford vertical slide?
Here's an online calculator: http://www.bilar.co.uk/cgi-bin/division-calculator.plI also need an Instruction manual for it and some guidance on what the dividing plates do and how to use them.
Not sure yet! I think its too big for the vertical slide, but I am contemplating using it with either the Amolco Head or Treating myself to a proper milling machine.
You can use a T slot clamping kit in the recess.My rotary table does not have those ears for bolting it down, it has a couple of small slots with what looks like M6 screws on the base and then recesses on the side.