Need help with a couple of things

[Vermont treasure hunter]

I found these a little while ago and was wondering about them. First, we have this oddly shaped bronze or copper key. Was wondering what this was for and how old it probably is.
And I also have this old aluminum plate. Has a very cool design on the rim and is pretty small. Was wondering how old it is.

 

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[Anduril]

I believe the key is for something called a "warded" lock, (which describes the type of lock mechanism), but other than that it's hard to say what it might be for.
Probably too elaborate (key cut) to be a simple clock winder, so maybe it goes to a low-security padlock?

 

[Sod Buster]

Aluminum dish looks to be the size of a tip tray. Not sure how old it would be.