Are you sure this is an Art Deco piece from the 1920's to 1930's or
is it in the Art Deco Style.
I believe it was around 1976 that there was a tightening of the gold
standard in the United States. Manufacturers were required to
create items with an actual fineness that was plumb. In other words
the karat of the gold stamped on the item had to be within three
one-thousandth parts the fineness indicated.
For a period of several years manufacturers were allowed to sell off
old inventory with the more relaxed quality. In doing so manufactures
stamped a large P next to the karat mark of any new items created.
This large P stood for Plumb Gold.
As for the makers mark, there are and have been many manufactures
that used the letter K inside a symbol.
Custom Jewelry - Handmade Jewelry - Antique Jewelry