Music Treasures circa 1964

As mentioned in RCR, Music Treasures of the World records were, at some point, sold by the Grolier Society. (My only evidence at the time: some MTW jackets refer to MTW as being "a division of the Grolier Society.") After RCR was published, I found a non-dated MTW direct-mail circular originating from Americana Interstate, Inc. -- Grolier's mail-order arm. I had assumed that Grolier's MTW franchise dated from the late 1950s. However, I recently discovered an Americana Interstate ad for the MTW club in the November 1964 issue of High Fidelity. (Headline: "THE BIGGEST HI-FI RECORD BARGAIN EVER!") By then, the records were being offered in "Electronic Stereo," in addition to the original mono. I've seen only one MTW "stereo" disc. It has a red label, as opposed to the standard blue.

UPDATE: I just found a couple of MTW discs in Americana Interstate shipping boxes, postmarked 1962. So the "no later than" beginning date of Grolier's MTW should be revised from 1964 to 1962. As if it matters...