A key designed by Charles Rennie Mackintosh to open Glasgow School of Art has been sold this week for £32,000.

The sale, which took place in the year of the 150th anniversary of Charles Rennie Mackintosh’s birth, was made to help raise funds for the restoration of the fire-damaged masterpiece building in Glasgow city centre.

Sir James King, who sold the key and is the direct descendant of the Sir James King, the Lord Provost of Glasgow from 1886-9 who opened the building with it, said: “I am delighted that a percentage of today’s sale will be donated to the restoration fund for the Mackintosh Campus Appeal.”

Sir James and auction house Lyon & Turnbull will donate a percentage of the sale to The Mackintosh Campus Appeal, the £32 million fundraising campaign launched following the blaze which badly damaged the Mackintosh Building in May 2014.

Designed by Charles Rennie Mackintosh especially for the opening ceremony of the building he designed, the key was presented to Sir James by six-year-old Miss Mary Newbery, daughter of Fra Newbery, director of The Glasgow School of Art, who then unlocked the door.

The key, which has not been seen in public since the opening ceremony on December 20, 1899, achieved a hammer price of £32,000 at the sale at Lyon & Turnbull in Edinburgh on Wednesday, with £8000 commission on top.

The key has been bought by Sir Ludo Shaw Stewart, owner of the Ardgowan Estate near Inverkip, Inverclyde where it will go on show at Ardgowan House.

He said “I am delighted that the key will remain in Scotland, it will take pride of place on show at Ardgowan House.

“I have a particular interest in the key and the Glasgow School of Art as one of my forebears was a founding father of the first School of Art in Glasgow, started in 1753 by brothers Andrew and Robert Foulis, a precursor and inspiration to the later Mackintosh School.

“The key is a beautiful object and we look forward to welcoming it to its new home.”