These are slotted screws, i am going to grind the heads off with a dremel. Time to stop playing nicely. 4 coils 8 wires...... Makes sense, these motors are not a special part, apparently they are used in alot of other things. No idea what or i would have the datasheet , but i do know how super critical stiring can be on these reactors, you need to be able to turn them smoothly from virtually zero all the way up to spin speed on a washer! (ok not that fast). Also some reverse, i dont know if reverse was on the controller for this one.
The stirrers might use "microstepping" just for smoothness. Micro-stepping defines discrete current levels for each coil, so they can position "between" discrete positions.