There is a letter up for auction (previously sold in 2014) from Ernest H. Shepard to a "Mr. Haack" where Shepard declines the invitation to illustrate The Lord of the Rings, which he declines (he was 90 years old at the time). ... 69-4b94-9eb8-aadb01127cb7

I would be quite interested to learn who Mr. Haack (or Haaek?) is and for which publisher (I assume) he was working with at the time. There is no information in the usual sources that I can find. Any ideas?

Letter from Ernest Shepard to Mr. Haack • 19 January 1970 (#821)