Well, as far as I understood and have heard, Gravity and A Ghost were written after the Rush of Blood sessions, as with Moses, Ladder to the Sun, Solid Ground, Your World Turned Upside Down and a couple others. As far as Deserter, Fingers Crossed, This Hollow Frame, and In Isolation...this is the first I've heard of them, so I couldn't tell ya.
[EDIT] Ok, I just looked up those songs (Deserter, Fingers Crossed, This Hollow Frame, and In Isolation) on the Q&A on coldplay.com, and it seems that you won't be able to get them anywhere. They're discarded tracks that probably will never see the light of day.