Not sure that I would agree with the term "journeymen" for anyone who flew in the Schneider Trophy Races. This was cutting edge technology for the day and also very high speed for the time.
Webster died at the age of 84 after reaching the rank of AVM. Waghorn died in 1931 after sustaining injuries in baling out at low level. Stainforth was killed in action in 1942. Atcherly also reached the rank of AVM and died in the late 1960's or early 70's.
Bert Hinkler and Harry Hawker were also part of the team for the races. Designers included R.J.Mitchell and Sopwith.
I have found reference to C.Howard Pixton and Bert Hinkler in the book AVRO Test Pilots. SOLO was written about Hinkler and there is a biography of Hawker that has been published.
I have even found a book about Lady Houston and there are a number of books about Doolittle including an excellent autobiography.
But for most of the others there is very little information available.