As was already said you would have to go to the Service Parts on the SS web site for part information. This can be tricky for replacing some of the older SPT's parts. The Service Parts section has only the current SPT's parts but does include the Mark V versions 500 to 520. As we know parts for the earlier Mark 5/V models are no longer made and so parts for them will no longer be available as they run out. Very few of the Mark V 500 table system parts are available anymore.
Back to the SPT's, as an example, if you need a wedge for the Jointer head and yours is an older one the current 5 hole wedge cannot replace the older 3 hole wedge. You would need to find a used one or buy a complete new Jointer Head. I had this problem on a 1954 Greenie Jointer I restored and was able to get a used one to replace a missing one. Other Jointer parts are the same going back to the original Model 4E Jointer. Using an Owner's Manual with the parts diagram and list can be helpful in locating parts. Typing in a part number in the search box on the home page can help find the correct part even if the number has changed. This is only true for the 6 digit part number starting in 1964 to the present. It will also tell you if it is no longer available by not finding any results. Other than the Jig Saw which has been discontinued and parts no longer being made for it, most SPT's can use current replacement parts but may require replacement of a complete assembly rather than an individual part.
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.