Any ideas on this find?

[huggis]

It's brass or copper it has a leaf pattern it's 3" in diameter two hooks on the underside and one threaded hole opposite the hooks.
Found with detector about 6" deep. I just don't have a clue

 

[cheech]

Maybe a lamp base

 

[bigfoot1]

cieling gas lamp base would be my take on it

 

[jewelerguy]

cieling gas lamp base would be my take on it

I think bigfoot is probably right. check out the fixture on this link. a wall sconce with a two-piece base looks very similar to your whatzit Vintage Hardware & Lighting -

 

[huggis]

Wow thanks for the link I think you guys are on the right track.
Thanks to all for your help.

 

[sutphin]

ALERT ,,, LAMP BASE ...

 

[huggis]

Solved thanks guys.