The book Kartenkunste was first published in German in 1910 (though some of Hofzinser's tricks had been sold for many years prior to that by the German dealer Conradi). Some of Hofzinser's material from the book was translated and appeared in The Sphinx in the early 1920s. I can't recall if the Spread Cull (it wasn't called that) is among those items.
The Racherbaumer piece is written from the point of view of someone who accepts Marlo's assertion that he created the spread cull because Hofzinser couldn't actually have done it as described since the cards at that time were too rough to slide.
This is not true, as I have handled one of the decks which Hofzinser actually used and the cards had very good slip and slide because they had been coated or treated with something, and were not simply plain rough cardboard.