There's a list for you :-

So the other Planet Stories books are definitely recommended. Can be impossible tell who wrote what with Kuttner and Moore some of the time.

SF-N-4.0 Kuttner, Henry and C. L. Moore : Destination Infinity - FREE
SF-S-4.0 Kuttner, Henry and C. L. Moore : Vintage Season
SF-S-4.0 Kuttner, Henry and C. L. Moore : We Kill People
SF-S-4.0 Kuttner, Henry : Beauty and the Beast - FREE
SF-C-4.0 Kuttner, Henry : The Best Of Henry Kuttner
SF-S-3.5 Kuttner, Henry : Clash By Night - FREE
SO-N-4.0 Kuttner, Henry : The Dark World - FREE
SO-S-4.0 Kuttner, Henry : Dragon Moon
SO-C-4.0 Kuttner, Henry : Elak Of Atlantis
SF-N-4.0 Kuttner, Henry : Fury - FREE
SU-S-4.0 Kuttner, Henry : A Gnome There Was - FREE
SH-S-4.5 Kuttner, Henry : The Graveyard Rats - FREE
SU-S-4.0 Kuttner, Henry : Housing Problem - FREE
SH-S-4.0 Kuttner, Henry : I The Vampire
SF-S-4.5 Kuttner, Henry : Mimsy Were the Borogoves - FREE
SF-C-4.5 Kuttner, Henry : Mutant - FREE
SF-S-4.0 Kuttner, Henry : Three Blind Mice - FREE
SF-S-4.0 Kuttner, Henry : Two-Handed Engine - FREE
SF-S-4.0 Kuttner, Henry : We Guard the Black Planet! - FREE
SF-S-4.0 Kuttner, Henry : What Hath Me? - FREE
SF-S-4.0 Kuttner, Henry : The World Is Mine

Lots of whom you will find :-

http://henrykuttner.bravehost.com/index.html

And some of the others online too.

Kuttner died in 1958, so public domain in a lot of the world like Canada etc.

There'll be more you can find here if you feel like it :-

http://freesflist.blogspot.com/

Actually, I thought Earth's Last Citadel showed more variance in style between chapters than most of the Moore/Kuttner stuff I've read. I think they each took on whole chapters at a time. A few chapters are obviously written by Moore (the lush descriptions are a dead giveaway), but there's a minor character whose hacky Scottish accent is everpresent in some chapters and totally absent in others. I think one author used the cheesy patois and the other didn't think to.

It's not like many of their stories had more than one draft.

Actually, I thought Earth's Last Citadel showed more variance in style between chapters than most of the Moore/Kuttner stuff I've read. I think they each took on whole chapters at a time. A few chapters are obviously written by Moore (the lush descriptions are a dead giveaway), but there's a minor character whose hacky Scottish accent is everpresent in some chapters and totally absent in others. I think one author used the cheesy patois and the other didn't think to.

It's not like many of their stories had more than one draft.

It's a wonderful book, no question about it.

I also enjoyed The Fairy Chessmen, which was another collaboration of theirs.

The Dark World is still my favorite Kuttner book.