When a book by publisher B has "First published by Publisher A" do you add that info to the book page of the B edition, or only to the work page?
© Writer, 1960
First published by Publisher A 1961
First Publisher B edition 1970
So is the First Published 1961 -- which really is when the work, not this edition of the book, was first published in some form -- or 1970: the first time this book was published in this specific form.
I always add this also to the book page. There is the credit "First published by" which you don't need in the work page.