Scott,
The best book you could pick up is the big one by Italian author V. Bobba. Brand new it is a bit pricy but worth every penny.
Here is what is looks like :
http://www.simpsonltd.com/product_in...oducts_id=2967
It is written in Italian and English side-by-side on the same page.
He has a second smaller book out in Italian only...about Lugers in general. But you want his first big book on the Swiss Lugers...
Here are a couple of used sources for less money...
http://www.abebooks.com/servlet/Sear...ts=t&x=54&y=20