Can anyone identify this mark please?

My husband got this for me on eBay after many years of marriage because I wanted a vintage looking ring. (I had worn a pretty CZ set that finally broke) Before I take this new to me set to be resized and reshanked can anyone identify this mark? Both the wedding band and engagement ring have the same mark. The middle stone is about .70 karats. Thanks for any information. (It did go through the eBay authentication process successfully)