Seeing as one of the new releases is a CP DC-8 let's take a look at one of their predecessors for both CP and Douglas. Canadian Pacific made really good use of its DC-6s and they didn't leave the fleet until the arrival of 737s in 1968/69:
Canadian Pacific Airlines Douglas DC-6B and Boeing 737-200 by rstretton, on Flickr
Canadian Pacific Airlines Douglas DC-6B and Boeing 737-200 by rstretton, on Flickr