Regarding the Kingston Trio, evidence suggests that the trio did own the building but that their studio recordings
were made at Capital Records Studio B in Los Angeles. The official Kingston Trio website does not mention the Sentinel Building, but
architectural critic Allan Temko, whom I trust, wrote an
obituary for Rob Moor in the San Francisco Chronicle dated 16 June 1997:
Rob Moor, a Dutch-born businessman who saved and restored the historic Sentinel Building at Columbus Avenue and Kearny Street,
died of pneumonia on May 22 at his home at Yardley, Pa. He was 85.
When [the Moors] arrived in San Francisco [in 1957], architect Henrick Bull, who designed a ski house for them in the Sierra, advised
them to purchase the Sentinel Building, a late Victorian steel-framed "flatiron" structure, surmounted by a copper dome, which was
threatened with destruction at a time when there was little interest in architectural preservation.
Yet the nine-story Sentinel was an authentic landmark on both historical and aesthetic counts because it had been built just before
the 1906 earthquake and fire by the notorious political boss Abe Ruef, who later went to San Quentin for his transgressions.
The Sentinel survived the quake and fire, and was put right again. But it had deteriorated badly (although Enrico Banducci's hungry i
nightclub flourished in the basement) by the time the Moors bought it in 1958 as an investment and renamed it Columbus Tower.
They never had cause to regret the stylish restoration by Bull, and they sold it at a profit 1 1/2 years later to a successful
young singing group called the Kingston Trio. The Trio in turn sold it to Francis Ford Coppola, who changed its name back to the Sentinel
and has his office there today. The building is now an official landmark.