With just five episodes remaining before The Late Show signs off for good, Stephen Colbert was joined on Thursday night by his predecessor, David Letterman , with the pair reprising a legendary bit from Letterman’s tenure as host. “Who owns this stuff?” Letterman asked Colbert as he stroked the fabric of the chair he was sitting on. “It all belongs to the CBS Paramount Corporation,” Colbert responded. “This is nice. It would be a shame if something happened it,” Letterman replied, before calling out several stagehands to take the set’s furniture to the roof.…