As already stated you can use other brands on the Shopsmith tools and SPT's. Although they are more expensive the Shopsmith Ceramic Abrasive products are very good quality products that outlast other brands. Shopsmith makes a wide selection of Sanding products not just for their tools but many sizes for other brands of tools. Their PSA Sanding Disks adhere better than other brands I have tried.
Mark V 520 S/N 09-11-01 completely upgraded to Mark 7, with all SPT's & more.
Model 10ER S/N R64000 first one I restored on bench w/ Shopsmith metal ends & retractable casters. Has Speed Changer, Model 4E Jointer, Jig Saw with lamp, a complete set of original accessories & much more.
Model 10E S/N 1077 oldest one I have restored. On bench w/ Shopsmith metal ends & retractable casters.