Vintage Cumberland "Mayblossom" Salad Plates are from the 1950s or 1960s and labeled on their bottom as "Stoneware" "Cumberland" "Mayblossom" "Japan".
These are in good vintage condition. One plate has two tiny indentations that have color in them so they are either very small chips or a manufacturing defect (See pictures). The other plates have no issues.
Approximate Dimensions: 7.25"in diameter x 1"T