Guys, buick man here from over at the post war Buick forums. I have gotten my hands on a mirror reportedly N.O.S. for Buick 57 & 58 but the underside stamping casting numbers do not jive with the factory box it came to me in nor factory documentation I have posted there. Perhaps one of you Cadillac pros could come on over and take a look at what I have. I have all the photos and information post over here at the link below. The Question: Is it Buick N.O.S. , Cadillac N.O.S., GM N.O.S or a period N.O.R.S.?

Here take a look and let me know what you think:

Mystery Mirror found in NOS 57/58 Buick Factory Box - N.O.S or After Market ????

Thanks in advance.