I had some electronic kits in that vein--not sure if they were Radio Shack or not. Just observing that I'm not sure how big a part of their business that sort of thing ever was.
I think your link observes though that someone could put such kits together and sell them over the Internet pretty effectively :-)
Look at this parts list: who's going to fill this void?
http://antiqueradio.org/econoceanic.htm