These are original dining hall plates for the private girls school Abbot Academy in Andover, Massachusetts. It was absorbed in the 1970’s as part of Phillips Andover. The Shenango logo dates them from 1930-1950’s. My guess is 40’s or 50’s.
Each plate is 8-3/8” in diameter. There are only light utensil marks on the surface. The crest, logo and overall plates are in excellent condition. I have 4 total. This listing is for ONE plate.