I have posted on my website the references on Tibet in the Volume III (China) of the Foreign Relations of the United States related to the Eisenhower Administration (1955-1957).
Nothing extraordinarily interesting except a remark from the US President during the 327th Meeting of the National Security Council held in Washington on June 20, 1957.
After a discussion of a report by a United Nations committee on the Hungarian uprisings, the Secretary of State, John Foster Dulles "noted a withdrawal of significant numbers of Chinese Communist troops from Tibet. He believed that these troops were being withdrawn in the face of Tibetan-inspired difficulties, on the one hand, and for reasons of economy, on the other. The Chinese Communists would presumably attempt to win the allegiance of Tibetans by different methods than the military methods of the past."
At this point in time, President Eisenhower "inquired whether the stationing of Chinese Communist troops in Tibet had not been considered a means of maintaining pressure on India. Mr. Dulles replied that this was certainly a consideration in the deployment of Chinese Communist forces in Tibet."