Well, obviously...nobody has anything on this for ya. It's hard to find them original these days, so your best bet will be to contact an expert. I like Paul Barry at Willys America. For interiors, there is also the Jeepster Man in NY, but I don't have his info at hand. Maybe someone else will pipe in with something. Sorry I don't have more for you.
Steve
The Jeepsterman is in Howell, NJ. I would suggest giving them a call 732-458-3966. They have a website too http://www.thejeepsterman.com, but if you call and talk to them you would probably get more useful information. The actual Jeepsterman Morris has passed on, but his daughter (drawing a blank on her name right now) is keeping the business going and has been working with this stuff for MANY years. I stopped in for some truck parts and she has all kinds of pictures, ads, and brochures of the early Willys that may show a nice pic of a stock interior. If not just pick her brain, she is very knowledgeable.
So was the Station Sedan a model just in the early flat fender years, pre 1950 1/2, or did it continue through the production run? I have not heard that description for the Wagons before.
Not sure but if someone has a pic of the interior as described it would be cool to see. I have never seen a station sedan designation or a different interior on a wagon that isn't a panel wagon.