No attribution yet, John. I have heard speculations of Queen City,
the nickname for Cincinnati, but I think it is only a guess.

Another way that we can be sure that it is a lithograph, not a die-cut
paper inlay, is that the cross-hatched texture of the paper is on the
black "Q" & "C" too, not just the white portion of the paper inlay.

As you know, this chip is not in the USPC photos from their archives.
It may have been made by Burt Co.