I suggest you read this thread: https://omegaforums.net/threads/longines-reference-books.46435/ I don’t think that anyone has really attempted to do an overall reference book on Longines. They are a somewhat older company than Omega and there would be a lot more ground to cover. gatorcpa
last month there's a Amazon seller posted the Longines Book by John Goldberger for 99$. Stupid me did not order in time, the book sold out fast.
The latest one, you can get, is this one, related to the 185 aniversary celebration ... By the way, it shows my #335 on the front page ... bb1964