I got a tip about this book:
'Instruction for Rolls-Royce Aero Engines "Eagle" series I to VIII and "Falcon" series I. II and III' from December 1917.
Produced by Rolls-Royce limited.
It is a 117 page document with a wealth of information and drawing of these engines.
It can be found here:
https://www.avialogs.com/All you need to do is make a free account. Then search for 'rolls-royce', click on the result and download it.
There are a lot more goodies on this site, but I haven't had time to do a thorough search yet.
Have fun,
Willem