The ejector for the 1912 was a simpler improvement on the original design for the Model 1903 that came into use about 1912 and used on the later 1903's & 1909's, the 1914's as well as the 1912's so you can widen your search for used ones. Numrich and Jack first both show them in stock listed under Model 1914 -
https://www.gunpartscorp.com/products/987590
https://jackfirstinc.com/index.php?r...ath=387_450_11