Johnson was born in Hull in 1903 and became the first woman to fly solo from London to Australia. She died in a plane crash while flying for the Air Transport Auxiliary in 1941.
Lamb said he thought the photograph was taken between late 1928 and early 1929 at Stag Lane Aerodrome in North London.
“For me it was a case of starting almost from scratch. I actually picked up a book on Amy Johnson.
“I was able to go through the chapters. It’d give me a specific date and it would say, OK, on this date, this was when this flight lesson happened.”
He said he believed the photo was a “rarity”, due to it being a “behind the scenes” shot.
“The one thing that struck me was there aren’t many pictures pre-1930 that you tend to see. Before she had a licence, before the records, it’s possibly one of the first few times she was ever actually on a plane.”