I'm sorry to say I can't tell you much, I'm in the same boat you are. I'm currently tearing apart my saddle and finding all sorts of things, I'm just doing a cleaning and replacing rusted nails/screws just the way I found them keeping a mental note of what goes where.
Antique Saddle Restoration
I haven't read it all the way through, but there are few things in here. The funny thing is, people tell you how to take it apart, but not how to put it back together...
The Stohlman Encyclopedia of Saddle Making (All Three) and Saddlemaking: Lessons in Construction, Repair, and Evaluation by Dusty Johnson , are some books I'd like to get along with a number of dvds.