A Timely Tip for authors --- at some time in your writing career you will ask for rights reversion of your books. Once you get them back you will naturally want to relaunch them to see your backlist staying healthy. When you get your rights back, you get the rights back to your ORIGINAL works - not the copy that was sold by your publisher. Meaning you will need to go back to your original version and re-edit the works to put them out again.
To that aim - KEEP ALL copies of your manuscripts forever...lol!!
I did, and will be relaunching my first Dragons of Challon books. I have my original manuscripts, so I can pull them up, redo my books and put them out. I have had a couple friends that didn't keep their originals so they are for a lot of work now. You cannot use the edited version, you have to drop all edits the publisher did while they had the rights, and they have to type their books into Word Doc form again. As I said, a lot of work. If you keep your copies you will save yourself a lot of headaches!!
Not that it should need saying - but you will need new covers too