The H&C mold with the eagle is a fairly modern mold, 1990's or later. It may be one of the fraternal Eagles Club chips.

The "GC" is in Larry Eastman's fine book, "Eastman's Illustrated Guide To California Card Room Chips & Checks" 1998

Greencourt Card Room
Nord Ave.
Chico, Ca USA
1964-1966

It is also in "The Gaming Table", Knapp, Myers, Wheelden, Audit Copy For 3rd Ed., 2002