I think they are inspired by, if not taken directly from structures that exist/existed in the 50s era. If I recall, the tepee motel was somewhere along route 66 (it inspired the Kozy Kone motel in the movie Cars), and I have seen an airplane gas station in Florida somewhere. I have also seen a lot of other strange looking restaurants and motels along the old roads in a lot of tourist (or former tourist) towns.
If you’re railroad is in the right part of the country, and if it’s in the right era, these could look at home along US HWY 1/41/66. But, just like in the real world, it can easily be overdone and kitschy.
I live very near old route 66. There were/are many of these interesting structures. There is a hotel made up of tepees(sp?) Along what is now I44 about 35 miles from my home. I’ve seen the icecream cone, giant fish, dinosaur, coffee pot, and milk bottle. I would like to put the icecream cone on my layout with appropriate details like picnic tables with customers etc.
There was a chain of the Teepee motels along many main highways. The main building and one auxiliary are located on US 24 east of Lawrence, KS, as well as on US 66, and I believe US 30.