She had seen the two sketches - Large Tent and La Gaiete Rochechouart - in Aberdeen in 1959, three years before the theft from the town's art gallery. When she recently noticed them in a sales catalogue, she alerted officials at the gallery, who contacted Grampian Police. The works were, last week, tracked down to addresses in London and Suffolk.
The two sketches are worth thousands of pounds and were part of a haul stolen from the gallery in 1962.
Detective Constable Nick Thom of Grampian Police, who co-ordinated the case, said: "This inquiry was interesting and fairly unusual as the crime had been committed nearly 40 years ago. The value of these sketches runs into several thousands of pounds - although given they were done by such an important artist they are seen as irreplaceable.
"We received information that the sketches had appeared for sale in a catalogue. From there, we were able to work forward and trace them."
Aberdeen City Council's assistant keeper of fine art, Lisa O'Connor, travelled with Grampian Police to bring the sketches back north. "We are delighted that the recent sequence of events in connection with these long-lost sketches adds significantly to the collection," she said.
Walter Sickert is regarded as one of the most important artists of the 20th century, and was one of the Camden Town Painters, a circle of London artists that formed shortly before the First World War to exchange ideas about art.
The recovery of the other artworks in the haul is considered unlikely, as the theft happened so long ago, and the Sickert findings were due to the combination of the chance sighting by Dr Baron and her clear memory of the two works.
No criminal action is expected for the original thefts, as the works have now exchanged hands several times, and the new owners bought them in good faith.Reuse content