Crescent Watch Case Co. Serial # 1969585. 3-Hinge, Open Face, Gold Filled, 20yr., Case.

From the Top, Case shows a Coin Edge, Thick Crystal, w/ late model Stem & Bow [1902-1915]. 

Inside Back & Dust Cover.

Expanded View, shows Front, Back & Dust Cover. 

Back is Engine Turned w/ Shield & Floral Pattern.
I'm using this Case for the Hampden, 1909, 18 size, 21 Jewel, Special Railway, with the Montgomery Dial. Right Era & enhances this 'Top of the Line' Movement [ON3L-5P, DR].