NBSR 422990 is an ex-CP caboose. It is outfitted as more of an “office” type car than a working caboose. It has a little kitchen, some bunkbeds, radio equipment, etc. It is nicely done up with cupboards, curtains and so forth. See below for an interior photo.
This caboose was originally CP 438871, built in 1974. It was renumbered to CP 434353, then CP 434916. When the internal CP shortline called the Canadian Atlantic Railway started, it was painted maroon and became an office car for the railway. NB Southern acquired the caboose when it bought CP’s assets in New Brunswick, and repainted it to NBSR colours and continues to use it as an office car / excursion car.