Hi, Weren't balance wheels produced back then of different weights?
jd should know if adjustment for 780secs is doable, it requires plenty of weight also space around the balance wheel.
In short was it posed dynamically or static.
Sorry, can't help you. I wanted these books for a long time and I wouldn't be surprised if you'd be able to identify the movement using them. The books list the movements by size and then have illustrations of the setting lever spring and setting lever to compare with. Unfortunately these books are pretty expensive so I've been hesitant to pull the trigger. @Mark demonstrates them at watchrepairlessons.com (Course 1: "Getting started")