About 40% of the book (60 pages or so) covers equipment from the time (including a exchange rate chart for various nations involved in Berlinin 1961, but base prices are in american dollars fo rmy ease LOL), agencies, background on Berlin, a time line, rules that are not horror/magic specific but just game concerns (encumbrance, what pulp is, minion rules, and so forth), some key locations (with pictures), a couple of maps (working on getting better ones for later books), and information on 11 agencies (including CIA, Gehlen, Stasi, KGB, GRU, US Army, and others).
The chapters on Essence (Chapter 3) and Magic (Chapter 4) are the only two real chapters that would be "horror/magic" specific while the Game Masters Chapter (Chapter 9) is about 50-60% material for the actual horror setting (monsters, pantheon and god information and so forth).
Truth be told, the only things I would do in a Espionage Sourcebook would be put stats of generic encounters, adventure guidelines and rules for Gadgets and Gizmos (the Mad Science rules in Berlin '61 could work in a nutshell, but thier flavor has the whole insanity and whack job touch to them). Maybe even a starting scenario and a "World of Espionage '61 Guide" covering major events of the early 60s, how the agencies interact and stuff like that.
As is Berlin '61 works as a sourcebook for Berlin centric adventures set during that time frame.
Id be more then glad to work on a compilation book to help create that setting option in more detail if anyone was interested in pursuing it as well.