I later discovered that the dish came from a pottery run by the monks at Prinknash* Abbey, which was a mile or so from Mrs MW's parents' house, so when I visited her at her home we would sometimes walk together down the beautiful Cotswold lane that led to the abbey.
That walk had another attraction - a small quarry dug into the limestone bank at the side of the lane. This rock contained....
....some superb Jurassic fossils. This is the first one I found, which I kept for many years until I passed my mineral and fossil collection on to one of my grand-daughters. It's a brachiopod, probably a Terebratulid, about 30mm long.This one, from the same quarry, came under the broad but rather beautiful title of Rhynchonella.So the Prinknash butter dish is some sixty years old and has been with us on all our travels. It's the sort of souvenir I treasure because it brings back such happy memories of so many people, places and events while at the same time still serving its original purpose today.
* Pronounced 'prinnish'