Thought readers would like to see this. AG Wiki says of Samantha's original outfit: "until around 1998, the only illustration of it was on the cover of Meet Samantha."
BUT I found an illustration in the first version of Changes for Samantha that shows the sleeve of the dress. Samantha is wearing her Plaid Cape in this picture, but you can see the cuff and a bit of the sleeve as she is lifting one of Nellie's sisters through a basement window at the time.
As I have said in some comments, my doll collection is very "by the books". Literally. So I won't try to make or buy an outfit for a doll unless it is at least mentioned, if not illustrated, in the original books. This find solved my debate over trying to buy or at least replicate this dress (I bought Samantha at a doll show and she came in a green custom dress; it's the one she's wearing in my "Samantha at the Beach" post.)