Here are all the extra pages from the three volumes released so far. (Untranslated, of course.)
Volume 1: http://imgur.com/a/KpLeW
Volume 2: http://imgur.com/a/57pun
Volume 3: http://imgur.com/a/Kst7t
Enjoy.
It would be nice if Rumia or some other kind anon would translate these and upload them to Batoto.