The Heinlein Archives are open.
This is a store where you can buy copies of Heinlein’s files. It consists of scrapbooks and notes, works in progress and other stuff that was found in Heinlein’s filing cabinets.
I am a little disappointed that you can’t buy any originals or hard copies. Originals would be very expensive, though. They sell you a PDF that you download (just like my name a star site).
Fr $3.00 you can buy a copy of Life-Line, Heinlein’s first short story, just as he typed it out to submit to Campbell. I might just go for it.