Regarding the CSA #8 (old Scott Catalog number #207) facsimile - here's the artwork from the Dietz card, which was copied by Tatham/Tasco to make their facsimiles, and probably copied by others too.

Also, for any lurkers in the balcony - this CSA stamp and some others are among the easy ones to check for authenticity because they were engraved (intaglio) stamps, so on genuine stamps the ink is raised and the surrounding white areas are often impressed into the stamp paper. Tilt the stamp in an angled light source to see the raised ink, and look at the back of the stamp to see if the intaglio design can be seen.
Oh, and the magazine article quoted above mentions that "a set of sheets of 25 [Springfield facsimiles] are known". They are not that rare. I own several sheets, picked up from different sources. However not all sheets of 25 being offered are "genuine" Springfields. One popular seller recently had a genuine set on
ebay, but at what I thought was a really high price.