When I visited in 1980, every car on the road was an Ambassador. Also lorries (trucks), motorcoaches (buses), scooters, motorcycles, rickshaws (bicycle and human-powered), oxcarts, camels, and elephants. We stayed in the Oberoi Grand, pictured at the top of your article. The soft drinks at the bar were Thums-Up Cola; no Coca-Cola or Pepsi, which had been kicked out of the country by the Morarji Desai government. I still have the Thums-Up bottle opener I kept as a souvenir.
We were in India to observe a total solar eclipse. Kolkata (still Calcutta in those days) was off the path of totality, so we left the city to travel down to our viewing location at Konarak in Orissa (now Odisha):
But the pictures in the Calcutta newspapers the next day were astonishing. People had been told (wrongly, of course) to stay indoors, as the sun’s rays were harmful during the eclipse. Can you imagine Chowringhee Road completely empty of humanity? Neither could I, until I saw it in the paper.
