Didn't search hard enough.
Here is an email exchange between Jay Rubin and some other people (the whole thing is interesting but I linked to relevant email).
Knopf did require a cut of about 25,000 words for the hardcover edition which has been carried over into the later editions. Murakami suggested a certain number of small changes but overall it was done by Rubin. Interestingly, for the Japanese paperback version Murakami included the small excisions he recommended to Rubin (but not the big ones made by Rubin) so in Japan the hardcover and paperback versions are a bit different.
To further amend my remarks above the WWII stuff, which is mostly in the final act is incredible and within the final 15 pages there is a page and a half that is the best writing I've read in a very long time. As a technical matter of writing the last act of the book is just as good -- and at times better -- than the first part but by then I no longer much cared about the larger story being told.