That's a good catch, Dan. This is Page 6 from Catalog 16-B, which was dated to 1938 in the file name. I don't recall where I got it. There is no publishing date in the actual text. It looks like a first time introduction, but I suppose I can see them running that again if they did indeed introduce them later in 1936 than when Catalog 15-A was published, or in 1937. The "B" in 16-B hints at a 16-A, which could've been late 1936 or 1937. (If you're wondering why I said 1939 last night, I don't have this 1938 catalog on my home computer. I really need to consolidate, but I've been waiting for TA 2.0.

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