I hope it's okay to post some thoughts re: regarding stubborn mirror haze. One potential cause is that the former owner may have inadvertently chemically etched the glass by using a harsh, inappropriate cleaner. Many of the more successful "home remedies" for cleaning stubborn haze (eg rubbing newspaper on the mirror) are actually working b/c they are mildly abrasive and are buffing out damage, rather than removing actual dirt. I would suggest taking it to a jeweler who can quickly look at it under the loupe and tell if the surface has been etched. If so, they should be able to fix this for you with a special polishing/buffing cloth or fine jeweler's rouge.
Another potential cause of patchy haziness is when there is separation or deterioration of the silver backing beneath the glass, which is more likely in very old mirrors or those in chronically humid environments. (I would not suspect this to be the case with your lovely bag's mirror, just including the possibility for the sake of completion.)