I have a friend in Maine who has 3 Cabooses, 2 boxcars and a refrigerator car in his backyard. The boxcars has a huge N scale layout 80 by 40 in the boxcars, the Cabooses are his kids fort and the refrigerator car is where his game (deer, elk, rabbit, moose) is kept... The cars is on an half mile of track... He’s looking for a Baldwin sharknose loco or a GE U boat.
There’s only two Sharks left in the world, they’re privately owned, and everybody wants them.
As to the article, repurposing retired railroad cars (freight and passenger alike) into houses and sheds was very common before postwar zoning in the 1950s.