Regarding Return to Ro-Busters, the book is described there.
As of The Cursed Earth Uncensored I chose to buy the limited edition signed by Chris Lowder and John Wagner, with an A3 poster from Mike McMahon original art. It is described in detail here (all in all it is my tenth version of that story).
Clint Langley's activity in association with Pat Mills doesn't end with Return to Ro-Busters collected edition as he is working on the collected edition of American Reaper, and he will take the art duty on Flesh! (images from Clint FB page).
Let's also pinpoint this interview of Pat Mills by Kevin Hall on the Facebook 2000 AD Review Page.