Thanks all. We are off to Cinque Terre (tickets to La Spezia but will probably get off a stop or 2 before). We had a booking in Milan but the owners claim to be closing the outfit after the end of the summer season. Been to Milan and seen the sights (except for La Scala) so no real need to look around.
I take it the Trenitalia tickets will be good for getting on and off anywhere on the route of the specific train between the beginning and end of the ticket (Milano and La Spezia).