Some years ago, the Elder Statesman and I decided to amalgamate our libraries getting rid of any duplicates.
Now that we only live 20 miles apart this isn’t an issue at all, and given our different interests there aren’t many times we both want the same book.
This does mean some series of books are split between the two houses. Russell’s three volume set of A pictorial record of Great Western Engines sees volumes 1 and 2 at the Elder Statesman’s house while volume 3 is at mine. Volume 3 being absorbed engines has all the weird and wonderful oddities and NG locos that float my boat but not his.
Similarly, Ozzie Nock’s Locomotives of the 20th Century is likewise split because the Patriarch doesn’t do diesels and electrics.
Occasionally we do want to borrow each other’s books and so it was last night I sent an email saying “when you come for lunch tomorrow can you bring Russell vol 2 and RCTS vol 5?”
They duly turned up today and so now I have some more gleaning of 15xx data to do.