Could this 4½ x 3½in (11.5 x 8.5cm) drawing, which is being offered at Mallams in Oxford on July 8, be it?
Reynolds knew the drawing only from a photograph but felt "on that evidence it looks convincing". Former curator at the Tate and Constable specialist Anne Lyles, who was consulted by the auctioneers, also thinks this is "most likely".
It has come from a house in Oxfordshire where it has been since being bought by the parents of the current vendor in the 1950s or 60s.
Dated 1819 in pencil, it has a label on the verso for a Sotheby's auction in June 1949 when the London saleroom dispersed a collection of John Constable paintings and drawings from the collection of Dr HAC Gregory.
The estimate is £3500-4000.