Vtg Shenango "ESQUIRE" Restaurant Ware - 4 Bread & Butter Plates - Laurel & Key

Set of four Shenango Esquire Restaurant, bread and butter plates. These are in great condition. They are heavy, as old restaurant ware should be. In addition to the Shenango stamp on the bottom, there is a hand etched code as well, maybe a way the restaurant kept up with their plates? Please see photos for details.