After two or more objects have been joined (not parented) together, is it possible to later un-join them, so they can be worked with individually?
select some faces, hit P to seperate those faces into another object
you’ll probably want to use the select linked command. Either with part of one object selected hit control+L, or just hit L [with nothing selected] with your cursor next to one of the verts of part…
Also, if you just have two joined meshes with no shared vertices,
you can go to Edit Mode and hit P. Then choose “All Loose Parts”.
Yes, z3r0 d, your first suggestion worked well. Thanks all!