It is of a large print depicting the Duke of Kingston and his servant outside Thoresby Hall dated around 1750-1760.
Mr Pugh said: “It is a photograph of a rare mid 17th century print of unusually large size (17in x 19in).”
“Despite being large and early it is not actually worth a fortune and will be for sale with some other early prints at the Caarmarthen Antiques Fair on 3rd and 4th March, price £40.”
“It is of interest not only because of Thoresby but because the Duke is attended by a black servant.”
Thoresby Hall is one of the dukeries, the four country houses and estates in north Notts all occupied by dukes at one point in their history.
The Pierrepont family took over the Thoresby estate in 1633 and built the first grand house, which was attributed to Talman, in about 1670.
The early 17th century house was remodelled, probably by Benjamin Jackson, in 1685-87, and burnt down in 1745.
Twenty years later John Carr in 1767–1772 built a new house on the same site and Thoresby Park was enclosed by William Pierrepont, 4th Earl of Kingston-upon-Hull in 1783.
The house was pulled down after just 100 years when architect Anthony Salvin designed the present house.