Now I'm thinking as follows :
An issue of The Occult Review consists of three different kinds of papers. They are --
1) the thick red paper for front and backcover,
2) the rough paper for letter-only pages,
3) the glossy smooth paper for pages containing photographs.
The article "Tarot : A Wheel of Fortune" by A.E. Waite was printed on the glossy smooth papers. And the lines of B&W drawings are really crisp and well defined, which is the obvious proof that they were photographically processed and printed from the original PCS drawings before coloring (the cloth of the Fool showing blank circles and no fruits). I believe it is safely assumed that the large 4 trumps are 1/1 size of the original. Waite himself said "I have selected four specimens taken direct from the drawings and naturally much larger than they will appear in the colour-printed set."(OR 1909 Dec. p.310).
Anyway it was natural for Rider Co. to make a set of photographical plates or films from PCS's original drawings at early stage. They could reduce the images down to the actural card size easily and faithfully and print copie and provide them to the Sprague & Co.. PCS might have used such set of copies for coloring. Furthermore, Rider Co. could reduce the image smaller and use them for adverts, which they did twice in 1910.
So many features of RWS shows the existence of photographic plates and processes. My temporal conclusion is that the 13 drawings of The Occult Review 1909 Dec. issue are the most faithful reproductions of original PCS pen and ink drawings because they are, as a matter of fact, photos. And what is called "oops"line of the Sun and its wrong XVIII number existed on the original drawing, presumably a PCS's mistake.