Transfer cabooses were used primarily in large yards and short moves on trains that needed little more than an office to run out of. Like this one, they were often cobbled together out of the scrap box, albeit a somewhat larger one than we modelers are used to.
The box car models a converted car from the late 60s/early 70s, when railroads were forced to remove the roof walks and all new cars had to be built with lower ladders and brake wheels, something that would have eventually been done when this car was shopped.
These were given to me as an unsolicited "Thank you" from another modeler for parts I had sent him. That the one was built by him and the other sports his weathering work makes them cherished members of my N scale roster.