The issue you will have is DNB. They  should not be showing on your report but they are since your score is low and if your not buying something from DNB they are have a funny way of sticking around longer then they should and even showing up later.. I know people who had negatives that they got taken off or had dropped off but then they showed back up and they then get calls from DNB reps trying to sell products..

Once you mess up your business credit it can be hard to fix since a lack of laws exist that protect  businesses and DNB is a bunch of scum bags.