Can the glass on an original rear view mirror be replaced?

[Mister-B]

I just bought an original ceiling mount rear view mirror off a '70. Everything is in really good shape, except for the actual reflective mirror part itself has some spotted places. Is it possible to have a new piece of mirror cut to fit the original housing without being expensive or a pain? I can of course always buy a reproduction part, but would prefer to fix this one if possible

Anybody done something like this before?
Posted via Mobile Device