Just guessing here, but the COP could be a manufacturers stamp, the circled c with 89 looks like a copyright mark for the year of manufacture. The 9 could be ring size.
Its my first ring I found with my MD and not sure if it is Gold?
Found it in a Tot park with pea rock ,so its roughed up but gold color.Its got a Black Onyx stone on the top.
You can see where the color has rubbed off on the edges...so just a junker..but hey a ring is a ring. No doubt it sounded off in the gold range as nearly all junkers do.