Q. Can one polish silver plates and similar during the Nine Days?
A. Kovetz Halochos (8: 3: n. 5), quotes Horav Shmuel Kamenetzki Shlit'a saying that it is permitted since those silver utensils are usually used during Shabbos, and for the honor of the day it is permitted.
Horav Shlomo Miller’s Shlit’a opinion is similar.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller and Horav Aharon Miller Shlit’a