Bust of John Gordon could fetch £2.5m – if Highland town agrees to sale

The Bouchardon bust has been sat in storage since its rediscovery 25 years ago because insurance to display it in Invergordon was deemed too expensive. Photograph: Highland council

In a hunt for ceremonial robes and chains, a dusty chunk of stone propping open the door of a storage shed in Balintore, Easter Ross, was almost overlooked.

But the doorstop turned out to be a marble bust of Sir John Gordon, the 18th-century MP and secretary for Scotland, whose father had given the family name to Invergordon, a small Highland town in Easter Ross. The sculpture was the work of Edmé Bouchardon, a French artist.