i wasn’t ware anyone would try jam peging. i saw a fellow at a show in so. cal. in 70’s demo it. and there is no indexing, you have a pointed stick/rod of wood with a stone on it and a lap and a vertical tapered spool with holes in it in a spiral. the indexing is you and your hand control of the stick. the closest i got to that so far is i have an o’brein faceting unit which is a controled jam peg system, i learned to facet on it that way. you do the cutting. a true jam peg you do all the cutting and control. the spool helps in setting angle. the spool is arched much like the facette faceter. you master jam pegging and you are a true master faceter. there are places all over the world that still jam peg, thats why many foreign stones dont look so hot nor facets meeting nor in the right uniform position.