I have some good news for you about making your mirrors like new. Worked for me.
The rear view mirror in my 1935 was just clear glass. I coated it on the back side with KRYLON Looking Glass spray paint and it is now like new. No Joke! You clean the glass then spray about three or four light coatings and you actually can watch it dry before you eyes.
The new mirrors are about $55. I have two of them. Will sell one for $30 plus the shipping. I suspect shipping will be about $7-$10. Send me a PM if interested,