Can anyone help identify this mystery integrated circuit?
Most likely a resistor network. This would be an uncommon color for an integrated circuit. CTS doesn't presently make integrated circuits, but they still make resistor networks. I can't decode the part number but their numbering system could have changed in 50 years.
7118 is the date code. It was manufactured in the 18th week of 1971.
https://www.ctscorp.com/connect_product_line/resistor-networks-rc-terminations/