I can’t remember. One Nguyen looks just about like another............But it was reported at the time that he left SV with the treasury in gold bars. And Wiki has this:
Life in exile
President Thieu
In his farewell speech, Thiệu said, “I resign, but I do not desert”,[4] but he fled to Taiwan on a C-118 transport plane five days later.[4] According to Morley Safer, the CIA was involved in the flight of Thieu, his aides, and a “planeload of suitcases containing heavy metal”
https://en.wikipedia.org/wiki/Nguy%E1%BB%85n_V%C4%83n_Thi%E1%BB%87u
Yup. Diem was the one the CIA shot when he wouldn’t play ball with us.
Not the “best” times for the US.