I DVR’d the first episode.
The CGI 707s looked fine, they had the original engines with the exhaust tubes, but didn’t use any flaps on takeoff.

There was a real DC-7 in one scene, it looked nice but they called it a DC-6.
In the same scene, set in Cuba, there was a C-47 with invasion stripes.

Finally, there was a CGI terrible S-58 (H-34/Wessex) taking off from the Pan Am building in Manhattan.