Thankyou all. I wonder, had the 707 concept had worked for Britannia, if the company would have purchased some new aircraft, as I alluded to upthread ? They were already in the business of buying factory fresh 737s so extending the idea to 707s would have seemed logical. On the other hand, the early 70s was a time when the 320B and 320C 707s were appearing on the used market as their owners upgraded to widebody jets, perhaps making these airframes a more attractive option.