If you can get a copy – P-38 Lightning by Warren M. Bodie, widewing Publications, 2001 – 276 pages of unsurpassed detail. Bodie had unique access to the Lockheed archive just before it was locked away in the ‘Iron Mountain’ secure storage and shredding facility (yes, really http://www.ironmountain.com/ is who you ask for Lockheed records now. They will say no).

Edit:

https://www.amazon.co.uk/Lockheed-P-38-Lightning-Warren-Bodie/dp/096293…

There’s a naughty version in pdf out there on the web somewhere.