Hi Alex,
I am very interested in your findings on the Bristol Blenheim Engine Serial number. Did you find out an answer.
My Grandfather ,Flying Officer William Henry Edwards DFC, was shot down on 12th May 1940 flying Bristol Blenheim IV P4905. His Colleague, Flying Officer Ronny Rotheram DFC was also shot down on this day in Belgium.
My e-mail address is:
mandyandross@bigpond.com
Regards, Ross Edwards