I also got a group of 4 carbon steel knives in yesterday. Not only were the edges in bad shape but the blade surfaces were a bit rusted. I taped some cardboard in place and applied some polishing grit to it and just rubbed those blades flat to regain some respectability.
One easy method to clean off carbon steel knives is with Ajax which is an abrasive powder cleaner wet a cork then then put plenty of the product onto the end of the cork and then work on the blade with the cork in a circular motion it is also good for cleaning off the ceramic stones it works well and it saves cutting your fingers on th edge .