THIS LEICA M3, SERIAL NUMBER 700740, FALLS WITHIN THE PRESTIGIOUS FIRST BATCH OF 10,000 UNITS (700001 - 710000). AS THE 740TH M3 EVER PRODUCED, IT WAS MANUFACTURED AT THE PIVOTAL HISTORICAL JUNCTURE WHEN LEICA ABANDONED THE SCREW-MOUNT SYSTEM IN FAVOR OF THE BAYONET MOUNT AND HIGH-MAGNIFICATION VIEWFINDER. THESE ULTRA-EARLY "700-SERIES" M3S OFTEN EXHIBIT DESIGN PROTOTYPE CHARACTERISTICS, INCLUDING UNIQUE VARIATIONS IN THE SHUTTER LEVER, REWIND MECHANISM, AND INTERNAL FILM PRESSURE PLATE DESIGN THAT DISTINGUISH THEM FROM ALL SUBSEQUENT PRODUCTION MODELS.