I'm saddened to hear the news about Chuck's passing. He was a knowledgable and helpful watch enthusiast, with a real passion for all things Omega. My condolences to all his friends and family in this difficult time. Best regards, Stephen Sugiyama
Your criteria seems to match Breguet, Watchmakers since 1775 by Emmanuel Breguet and available through Antiquorum . Cormac's review of this and other books on Breguet is here: The Great Breguet Book .
Railmaster, 36.2 mm 2504.52.00 (bracelet), 2804.52.37 (aligator strap) Automatic, co-axial movement, official chronometer, stainless steel case, transparent case back, water-resistant to 150 m.
Hi John, Here's a movement photo of ref. 5197/cal. 591A scanned from Revolution , edition "USA 1": And a movement detail photo by Alberto of what is called the cal. 5770 (?) from this year's Basel report: Best regards, Stephen Sugiyama