I sold one of these a couple of months ago here on Oldgas, but this one is different. There were at least two different versions, with different "GM" numbers at the bottom right. This version also has unique grommets that are very small and don't lap onto the front of the sign very much at all.
Condition is fantastic. It would be mint with the exception of one edge chip, shown in detail photo.
This came out of the same estate in St. Louis as the other one I sold, and the tanker truck sign that I bought (NFS).
Price $75 (plus ship)