Truman, polish the worn spots with flitz metal polish lightly to smooth
them out.
Then try some good quality cold bluing solution, polishing with
0000 steel wool in between applications.
If you do not get a great result, then decide to re finish the gun
at Smith and Wesson or a shop such as Fords.
In my opinion a quality re finish on a late model gun does neither
add nor detract from the value.
But,, IT must be a top quality job, otherwise it detracts greatly
from the value.
Good luck
Allen
By the way , How much was it ?? $$ IF I may ask?