I remember the DC3`s and Islanders, and even a Cessna Seaplane all in Yellow Check scheme, but the DC4 was before the DC3 days, i think they only had it in for a week or two, and were probably evaluating it as it was before they had any contracts awarded and got the Daks.
I used to work for them as a “Saturday Boy” when i was 16, and was used to mixing with Cessnas, Pawnee`s & a Fokker Triplane, so a DC4 outside the Hanger was a bit different!