Sparton 661-RP radio and recording phonograph

Hi, I'm new to the forum. I belong to the Antique radio Forum also and was unable to get any info there on this unit. It's a 1941 vintage radio and recording/playback phonograph unit. I think I've figured out it is 78RPM. The playback cartridge is an Astatic which I have not tested but according to my searches probably will need replacement or rebuild. The cutting head is I believe magnetic. The mechanism under the cutting head arm engages a long screw drive that moves the arm as the turntable rotates. My questions are, what kind of blank disc do I get to try it out, and does anyone have any operating instructions for this kind of tuntable?

Thanks,

Corby Dawson

The cutting head is a piezoelectric crystal. I found this out the hard way years ago.