Imperial Airways ended in 1939.
Imperial Airways was created on 1924-03-31.
Imperial Japanese Airways was created in 1938.
Hellenic Imperial Airways was created in 2006-05.
British Airways Ltd. ended in 1939.
There is some Imperial Airways stuff at the Croydon Airport Society archive (http://www.croydonairport.org.uk/)
Discovery Airways ended in 1991.
ArGo Airways ended in 2010.
Angkor Airways ended in 2008.
Ghana Airways ended in 2005.
Wataniya Airways ended in 2011.
Euroceltic Airways ended in 2003.
Tropical Airways ended in 2003.