In 1999 I wrote a book called ANTIQUE FLY REELS "a history and value guide". Now out of print. You may be able to find a copy online or at auction. Lots of patent analysis, drawings, B&W photos and dating information. I also co-authored ANTIQUE & COLLECTIBLE FISHING REELS "Identification, Evaluation and Maintenance" with Harold Jellison. Last edition (5th printing) was in 2002. Out of print, however there should still be a few copies floating around. A general work and not specific to fly reels.
Good Luck - Danny
http://www.NorthwestFishingBooks.com