“Farmer” Lawson

I think you will find that there are quite a few published sources that cover this period of 19Sqn operations and the Battle of Britain in particular:

“Spitfire Squadron” by Dilip Sarkar ISBN 1-871187-09-5 also
“Fighter Squadron” by Derek Palmer ISBN 1-85421-075-0

If you are going to publish a book then clearly you need to check out the 19Sqn Operations Record Book at the National Archives, Kew.

Steve