Unknown busch sign

I bought this sign because I've never seen one like it before. I don't know the year or if there is something missing. I've been asking around for awhile and no one knows anything about it.
It's labeled item 8m and on the back it's stamped with the carpenters union stamp district of St. Louis. Behind the front pane of glass, the red ribbon is tin.
If you have seen one like it before please let me know. Thanks for any help.

HEY for those that loved the sign and others that are curious about the sign. Budweiser told me it was a point of sale sign from 1956. Whatever that means?? But the real kicker is that it's a Michelob sign. That's what M stands for in Item 8M. Then I found out they didn't bottle Michelob until 1961 so I guess it's rare and priceless. What do you think? Thanks for reading.