I mentioned a while ago that the three Heinlein stories that he hadn’t allowed to be reprinted in his lifetime had finally been collected.
What I didn’t realize then was what a service to the Heinlein fan the SFBC had done with the collection, Off the Main Sequence. It is all of Heinlein’s short stories that aren’t in The Past Through Tomorrow. With these two books, you don’t need any other collection (including Orphans of the Sky, which is a fix-up of two novellas.) This and the 32 novels are all you need for the complete fiction.