Hi Paul
I think you will find a lot of history if you visit individual lock manufacturers sites. Sorry I can’t give you links. Chubb Assa Abloy, Imperial Locks, Bramah.
Remember Lock museum too. Also ‘chubbarchive’ that’s an individual’s site.
Search safe companies as well Chatwood, Milner, mosler, Yale, Withers, watch your thread here I’m sure you’ll get more info.
Keep us informed on how you are getting on.
R