a GM carb. any idea kind/age?

[Viddy]

I was hitting an old foundation today and found this (in the pictures).

Part of a GM carb. I posted a pic next to a quarter so you can see the size as well as a pic of the back.

Any idea how old? what it is from?

The front has arrows with the words 'hot' and 'lean'.
Also, the 'made in USA' and 'Rochester Products'
The back has, what looks like, some kind of spring in the center.

thanks in advance for any help!

 

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[Creeker]

Lean rich adjuster from a one barrel Rochester gm carb. 1932-1956! There is one on eBay right now that clearly shows your part. Item no # 380410048990 in case you wanna get a look at the full ad

 

[cheese]

It's an automatic choke. Looks to be 1950s.