I don't know if EMCO made "Imperial" turret Discs, since i live in Europe..
But.. the EMCO Compact 5 CNC indeed has 3 Slots and 3 Bores.
There is a 3D model of the EMCO Compact 5 CNC on Grabcad, made by a fellow dutchman, and i have that 3D model.. because i want to modify my EMCO5 a bit..
the Slots are 14 mm high, and 12 mm deep, so a ½" tool will fit.
the Bores are ø10 mm, so you might want to order tools that are slightly bigger, and turn them down, or Drill the holes a bit bigger.. it's cast Iron.. so that shouldn't be rocket Science..
Another option could be, making a new Turret Disc, with all the holes or slots you need.. (That is what i intend to do, so i can put tools for a certain job in there , and just replace that disc..