The pilot's son sent Kodak slides that he found in 1991 for analysis to a research chemist for examination. The slides were a series of photos taken by the pilot in 1954 and were pictures of when the son was a young boy. In the background of one of the slides a glimpse of the painting can be seen in the background. The examination of the slides prompted the chemist to send a letter to John Richardson - a Picasso expert - to inform him of the findings.
McCrone Research Institute Confirmation of Slides
The Kodak slides were also sent to the McCrone Institute to confirm the analysis of the slides.