Thanks for the explanation Worf, I hadn't considered that geo-political concerns would play a role, but of course they would in reality. I imagine that it was India's development of atomic weapons and flirtation with the then USSR that had Uncle Sam giving them the cold shoulder and of course there weren't too many immigrants of Indian heritage back then to be served by the Indian government.
The French aircraft in the IAF would explain the stop in Paris (ORY).... that did have me wondering when one of the earlier posters revealed the routing from Pune to London. Was every stop on the courier flight for a purpose (outside of refueling and oil for those thirsty Wright engines!) ?
Regards
SHJ