Im not an expert but I find it hard to believe that bailiffs can take your mothers belongings and ignore the fact that it belongs to her. They are a law unto themselves and even commit what looks like theft to close their books. It was not your mother who owed the debt so why should she have to prove that her belongs are hers? Check with the cab with a view to claiming against the bailiffs in the small claims court for the return of her stolen possessions. Their actions may have been illegal. You may even be able to send in the bailiffs to the bailiffs. I also find it hard to believe the DVLA behaved the way they did while the appeal was still pending. Try using their complaints procedure.