I went to Mark Twain from 1958-1960 and you are correct, the student body was not very diverse in the Sunset at that time. I can only remember one African American student, Arthur Turk, who lived near us on 46th Avenue. The health department was right next door to Mark Twain on 41st Avenue and Pacheco as was West Sunset playground where I played Little League baseball. Add in Giannini Junior High plus the Ortega Branch Library and it was a huge complex. Sand dunes to play in to the east and south of the campus until Saint Ignatius HS was built in the late 1960’s. Long ago and far away.