Question about older Pioneer PD-75 Player

Does anyone know or remember if the Pioneer PD-75 player used a bare aluminum platter or whether it was supposed to have a mat to place the CD on? My used PD-75 came with no manual so I'm in the dark. Seems strange to set the CD on a bare platter. I was given a manual for the PD-95 transport and its manual indicates the PD-95 came with a "sheet" for the platter but I don't know the composition.