Il Nuovo Postiglione - Goodbye 'Downton Abbey' auction and UK exhibition announced

The sale by London auction house Bonhams, which will feature everything from dresses to a clapper board, will run online for just under a month from August 18.

It comes ahead of the release of a third film -- "Downton Abbey: The Grand Finale" -- in cinemas in September, and follows six highly successful seasons of the show on the small screen.

Bonhams is marking the occasion with a free "special exhibition" at its New Bond Street location in the British capital open to anyone and featuring some of the sale items, it said.

"Downton Abbey is an exceptionally well-researched piece of storytelling on aristocratic society in the early 20th century," Charlie Thomas, of Bonhams, said in a statement announcing the sale and accompanying showcase.

"The costumes and props show the impressive attention to detail that brought the world to life on screen and making it so beloved by millions across the globe."

Among the higher priced items going under the hammer are the Downton Abbey "bell wall", the servant call system which featured prominently in the television series. It is estimated to fetch up to £7,000 ($9,400).

Various dresses will be available, including a wedding costume worn by Lady Mary Crawley -- played by actress Michelle Dockery -- in the first episode of season three priced at £3,000 to £5,000.

Meanwhile the clapper board used in the production of the film "Downton Abbey: A New Era" is set to cost £1,000 to £1,500, while an autographed script of episode one, season one, is estimated to go for £600 to £800.

Q.Bernardi--INP