Front surface mirrors will not use silver since they are essentially unprotected against hydrogen sulfide in the air which would otherwise quickly turn them black. A conventional mirror (looking glass) has a thick protective coating on the back to protect the silver coating.
So get out your buffing pads. One must suffer for one's art.
I do already. I carry around a RB-67-with a tripod
Well it's good to find out that it can't be done. You don't go crazy trying to make it work,and you can spend the time on something else