It needn't be that elaborate especially for a single setup. If you set your compound and turn a tapered slug, then just chuck up some ally in the 3-jaw, bore it through, turn the taper for the slug, turn the OD for a close fit to your part with a back-shoulder, cut the slots, de-burr then mount the part up and tap in the slug. It won't move.
To release, tap the slug out from behind with a long knock-out bar through the spindle.