Watercolor drafts of the Thoth Tarot by Lady Frieda Harris. Two versions of the Atu I (The Magus), and early versions of Atu XVIII (The Moon) and the Knight of Disks. Found here.
I think I like the first Magus better than any of the other alternative versions (and perhaps, oh heretic!, better than the final version). I still wish I could find an image of the draft of Atu 0 that resembles Harpo Marx!