ANTIQUE MURDOCK 1920'S WIRELESS RADIO - TUNING CAPACITOR BASE PLATE

Description

I am guessing at what this is.  is marked Murdock...    see pictures.
But I think it might be a base plate to make a crystal radio in the day.
Please let me know if I am wrong, thank you
as found, as is. no cracks
from ebayer:
This looks more like the base of a tuning capacitor than a detector.
Please see all pictures and use zoom feature.  Often the pictures describe the item better than words.!
Also please see the other 9,500 vintage radio related parts and other great antiques and oddities I listed.
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