I, Ned Behrman, was the 'cellist in a regular quartet that played at Mary's house during the approximate years 1980-1983. We played the standard repertoire, except that at Mary's urging we went through every Haydn quartet in the four-volume Peters Edition during that time. She was anxious to play them all before she died. And so we did!
This picture was taken at a birthday party. I didn't record the date.