I respectfully disagree. I think a well tuned scraper is better at fingerboard dressing, especially in this case. A block plane can be too aggressive. You could chalk the underside of the string, slightly rough up the fb ( enough to take the "polished" surface off) in the questionable area and observe the contact. Slowly touch up the area just till the chalk stops marking, at which point the buzz should also be gone. Best of luck!