Please note:
This is a vintage piece, many years old, so has seen a lot of use.
With this type of piece the mirror is held in with metal clips, and over time the clips move against the mirror causing minor chipping, please see pics below.
This is a regular occurance, but adds to its patina.
There area also minor pitting areas to the mirror which is also common with these pieces.
Further pics can be provided if required, but I personally feel that this is what is expected from pieces of this age.