Well, the 2000 is still not as fine as the final finish put on straights. Generally if you want a mirror finish you must do polishing and buffing after the sanding phase using a series of polishing compounds. Is the 2000 leaving shiny scratches? As in, is it cutting through the black rust or grey that you said remained? If it is you are on the right track. Make sure you sand the entire blade evenly and thoroughly. You are aiming for as homogeneous a finish as you can get. Once you are there, you can start the buffing and polishing phase. Here is a nice intro to buffing and polishing. James.