At a local thrift store we happened upon 5 small clay soup bowls with handles. Three which have been used are marked "Redwing Provincial Ware 22" but two (which look unused) have a different mark on the bottom. It appears to be an etched vase or jug shape with the letter P inside it and the number 72 USA underneath. We are curious as to whether these are also Redwing pottery? If not what might they be?