You can get discs here.http://www.apollomasters.com/index.html
I'm pretty sure that is a home recording unit. I don't have any experience with the Sparton, but most all of your home units don't have the automatic feature of start and ending grooves. Most are cutting arms ride on a feed screw and you just set the arm down on the blank and begin recording. When done simply pick it up off the blank. It's possible to cut start/end groove manually with some home units but it's not easily done.