Here's a cute one. The left stamp closely resembles, shall we say, the #205C Special Printing. The right stamp is the Reddish Brown copy that Luff noted in his 1902 book as being accompanied by a note from the Third Assistant Postmaster General as having been transacted on February 10, 1882 - two months before the regular issue date of April 10, 1882. As you can see, the right stamp has a good amount of raspberry in it (though the scanner is somewhat overstating the color) and shows all the diagonal shading lines in the vignette. Further, the paper, even with the stamp having gum, is a bright white.
Mooz quipped that if this stamp ever surfaced it might be accurate to assign it a catalogue number of its own - 205Ca. Well, here it is! It has transacted many times since 1902 but it wasn't until Mooz published his research in 1992 that philately understood that the Special Printing was ordered by the Third Assistant PMG BEFORE the regular issue. 5000 were paid for in February and another 5000 in March. over 300 are recorded sold, but many more, like this one, were likely given away to dignitaries.
This stamp's existence poses a problem for #205C. It is probably the only Banknote Special Printing having documentation of where and when it was issued. It also has a different color than the accepted 205C, a different paper from the accepted #205C, a different impression than the accepted #205C, AND is gummed! So, how did all the accepted Scott #205C's become the accepted Special Printings?
I think Mooz is correct that most orders of #205C were filled with the ordinary stamp. But I think that's only part of the story. What I think actually transpired was that the ABNC sent along whatever stamps they had on hand in early February of 1882 as a stopgap to allow the Third Assistant PMG to ration them out. Mooz records many orders for the new Garfield stamp only partially filled prior to April. I think all the stamps issued prior to April of 1882 were from a printing of a few hundred reddish brown stamps on bright white paper, of a complete impression and gummed, like this one.
The ABNC's first task was to issue the regular Garfield, which was several months late in getting out. Only after the millions of regular Garfield stamps were printed for general distribution did ABNC set about fulfilling the Third Assistant PMG's order of 10,000 stamps, which were printed from a cleaned, yet worn business plate, likely on a proofing press away from regular stamp production, and with the same ink and paper as the first regular printing. These would include all of the recognized #205C Special Printings, which is why some of the regular issue can so closely resemble the Special Printing.