For sale - 1957 'Carnival of Books' interview acetate

Hi all, I was wondering if anyone might be interested in making me a serious offer for these acetates. As far as I know this is a unique item (the Library of Congress in the U.S. supposedly has a tape recording of it and I don't know of any other copies in any format), and I believe it is the earliest audio interview of Tolkien that exists. It's an interview he recorded for a radio show aired in Chicago in 1957. The audio adds up to approximately 15 minutes total, the interview material covering about a third of that.

Here is a sample of the audio which I recorded directly from the acetate: Sample recording

Some additional information can be found in these sources: H&S Chron. p 527, RG p514, 516; Annotated Hobbit p8, 210; ALA Bulletin, Feb 1957, p120, etc.

To give an idea of what I'm looking for I've had an offer of £3,200 to sell this on consignment but I would prefer to sell it more quickly. Please feel free to send me a direct/private message with any questions. Thanks!