A bit. The design actually goes back to the 1930s, although it first flew in 1940, if memory serves correctly. The CW-20 was the first pressurized airliner. The Army never flew them pressurized though. Give me a couple of weeks and I will get a full rundown for you. I am working on a presentation on the C-46 for July at the museum. Once I have all the info compile, I can tell you a lot more. I am taking a week off from research as I just gave a presentation over the weekend.