Yancy Smith, a researcher in the media studies department at The New School in New York City who is examining "the culturally loaded meaning of the typewriter" and is a "neophyte typewriter collector" himself, spotted this item for sale on US eBay and emailed me about it this morning.Some Typospherians may have seen it themselves and wondered. It is listed by a seller in Kreamer, Pennsylvania, as an "Antique 1905 Turn Of The Century Type Writer Keyboard Class Learning Tool".
Clearly it is no such thing. My initial guess was right. It turns out to be for a Linotype machine. I'd say this is the patent model.