Below is 4 pictures of my version of the MKII.
It uses MDF discs instead of the aluminum ones. It doesn't have the sharpening box attached which I use to guide my sharpening.
Here it is with the mdf disc removed. The disc stays in place by way of 2 1/4 pieces of steel that stick up 1/4".
This is the underside of the sharpener
This is a closeup showing the 2 pillow blocks, the pulley and the underside of the platter.