1.1" US Navy Mk I (28x199mm SR)

Is C.B.& C. Co. Clark Brass & Copper Co., Elk Grove, IL?

Probably Chase Brass and Copper (Cleveland). That question has come up before.

Thanks, Chase Brass & Copper it is, found the thread you’ve mentioned viewtopic.php?f=8&t=14571&p=103628&hilit=Chase+Brass+and+Copper#p103628

Here is an excerpt of a contract delivered in 1942 to the U.S. Naval Ammunition Depot in Nevada;