I'm not sure what exactly has gone on behind the scenes, but a number of books long published, championed and supported by Peter Owen in their Modern Classics series seem to be slipping over, in paperback editions, to Penguin Modern Classics, with some very nice covers. However, Peter Owen seems to have retained the hardback rights, and are reprinting them as what they are calling Cased Classics. (See other examples of paperbacks at one publisher, hardbacks with another here and here.)
So here are the new/imminent Penguins...
..and here are the beautiful hardback Peter Owens, with diecut covers over fully illustrated boards (click for much bigger versions).
The moral of this story is that the much less attractive edition of The Ice Palace which I bought a couple of months ago, before I knew about any of these, was not a good investment.
(More Peter Owen coming soon: their beautiful and intriguing World Series books with Istros)