Up for sale is a de luxe 747 first fights set of 3 First day covers PanAm, Alitalia & TWA envelops all related as they are of first 747 flights PanAm flight 111 of a 747 Rome-New York, 
TWA B-747 first flight Rome New York 
Alitalia first flight 747 Roma - New York, this flight accommodate Astronaut Nil Armstrong and was honored with his name and the moon landing on the Alitalia envelope.
All are Posta Vaticana.
The set Originally purchased June 1970 for price of 4.25$ ( Price of a gallon was 0.33$)
All airlines are Ceased
Alitalia - May 5 1947 - October 15 2021
PanAm - October 19, 1927 - December 4, 1991
TWA - July 16, 1930 - December 1, 2001

Nil Armstrong R.I.P - August 5, 1930 - August 25, 2012