OLD MEXICO STERLING ROADRUNNER CUFFLINKS - MARK/SIGNED

THIS IS A PAIR OF OLD CUFFLINKS THAT HAS A WONDERFUL DETAILED FACE DEPICTING A ROADRUNNER, CACTUS AND MOUNTAINS IN THE BACKGROUND. THE BACK OF THE CUFFLINKS READS IN A CIRCULAR PATTERN - STERLING MEXICO - AROUND A MARK OR SIGNATURE THAT I CANNOT QUITE MAKE OUT (MAYBE - MMS, OR - MVS?). THERE IS ALSO A HALLMARK-LOOKING MARK THAT MAY BE A "3". I DIDN'T KNOW IF THE PHOTOS WOULD SHOW IT WELL, SO I TRIED TO DRAW OUT THE TWO MARKS (SEE BELOW). THEY CAME FROM A SAN ANTONIO, TEXAS ESTATE AND MANY OF THE ITEMS THERE WERE FROM THE 50s/60s, SO THESE MAY BE THAT VINTAGE, BUT I AM NOT SURE.