Registering kitbuilt

Dude says he has a kit built aircraft, bult by someone else. It was registered and flying but said he let the registration run out when he quit flying. So, if someone was to buy this aircraft, what kind of a conundrum would this be ? Would this be as bad as the Turbo Encabulator?
Bob

Plane with expired registration simply needs registration renewed. If it's been expired a long time, might have to obtain a new N-Number but otherwise not a biggie.