Douglas Airways had the more common 'short-nose' version.
Rabbit 1 They certainly did. DNN, DNP and DNX.
If memory serves correctly, DNN was actually the prototype Trislander and along with DNP were the only ones operational for the last year or so of Douglas Airways existance.
DNX was a 'hangar queen;' Was supposedly having a major inspection but for the nine months I was there never moved from the maintenance hangar.