Savage couldn't resist tinkering with the design, however, and the constant changes probably combined with massive overproduction in the first couple years to eventually doom the pistol on the market.
The second pistol from the left is a Model 1915, introduced as a response to Colt's wildly popular 1903 "Pocket Hammerless". One can only imagine that meeting at Savage headquarters:
"These people keep buying Colts!"Thus the 1915, which eliminated the external spur, blanking off the slot in the breechblock, as well as adding a grip safety and a last-round hold-open feature. Unfortunately, the pistol was more expensive to make, sold at lower profit margins for the company, was trickier to disassemble, and the last round hold-open feature was fragile and breakage-prone. Tooling up for Great War arms contracts put paid to the 1915 variant after less than two full years of production, making it the rarest of the little Savage variants.
"They like it because it's hammerless and Colt's advertises that it won't snag on coat pockets."
"But it has a hammer! It's just internal! Our pistol really is hammerless!"
"But people see the spur and think it has a hammer..."
Lastly, the pistol on the far right has the spur-type hammer that was always available as an option, but became standard on the final variants of the 1907 and was continued on the Model 1917.