Even w/a rough stone and a pilot, the bowls aren't uniform, I have carbide pilots that are hard & accurate...but if Your not patient(VERY) the side loading can snap them. That goes for stones and multi-blade/bit cutters, but really for single cutters ie Serdi etc. If You lay out Your dimensions accurately on card sheet, and set the width/height w/markings starting from a guide center-line, You can exacto-cut a template out and insert it in the guide and work with a burr till You're really close. Have You used/seen the ones Mopar sells/sold?
