The Rockford Silver Plate Company operated from 1882 to 1925 !! Before that it was the Racine Silver Plate Co. but it burned and the company was renamed Rockford Silver Plate Co. In 1925 the company was sold and continued operation as Sheets-Rockford Silver plate Co. until 1956 !! All records were destroyed when it was sold so no way to date it accurately !! As to cleaning it,, just use a good silver polish,,I suggest Wrights Silver Polish !! But you can try some plain old ketchup if it isn`t too bad !! Very little silver on these items so only clean a couple of times a year with the polish !! Wash and buff in between !!