What does OJ mean on the inside of my band?

by Staci
(Gladstone Oregon)

I bought an engagement ring (off of ebay) it was advertised as "vintage" antique, though nowadays, so many New items look vintage, so I don't know how to tell for sure. It is stamped 14k, but it also says oj on the inside band, near the 14k stamp. Any ideas? Is there any way to tell if it is a vintage piece or a replica??

Thank you! :)