Google "Santa Fe Skyway" for what images are there (a lot of separating the wheat from the chaff). I'll send what I've managed to find (including a couple of a model done of it). I'm ordering a copy of the ATSF Historical Society's magazine with articles on the short-lived operation (only a few years 'til the ICC shut them down) and on modeling their aircraft. Apparently the Southern Pacific in California tried a passenger airline and that has potential for some whif possibilities
Well, it seems that decals for Santa Fe Skyways already exist from Vintage Flyer Decals. Interesting whif would be to extend the concept beyond the DC-3/C-47 and DC-4/C-54 to other aircraft they might have operated if they had continued. Beyond that, there are several whif possibilities for airline affiliates of other railroads if you're interested.
On a second look-thru, Vintage Flyer does one of three C-47s and one of four C-54s; it should be possible to do decal sets for the remaining aircraft. One set for the C-47s and another for the C-54s with the decals set up so one complete aircraft can be made but with the necessary differentiators (name, NC number) for all the ones VF does not cover.