Vintage Sterling Silver Saint Christopher Medal Pendant Necklace

Vintage St. Christopher Protect Us Medal pendant is signed Sterling and a maker's mark and it is inscribed 7-31-69 on the back.  It measures 1 1/2 inches, including the bail, by 3/4 inch wide.  It is on a 24 inch sterling silver box chain and the weight of the necklace is 11.2 grams.  It is in great vintage condition.