KH question

File that surface down to get rid of the "divots"
I use one of these files, about 3/8 inch, square, in my rebuilding of those calipers.
I have seen, done, worse ones, that what your picturing.
Don't worry about filing too much, nothing bad is going to happen.

MAC File 001 (Small).JPG

KH Calipers 65-72 001 (Small).JPG