Several companies offered ejectors for Parker Bros. hammerless doubles. One of the most noted was Moran & Wolfersperger in Chicago --
American Field, September 5, 1903.jpeg
73542 03 M&W Ejectors in GH.jpg
For years after Mathew E. Moran and Ross C. Wolfersperger went their separate ways, Gus Habich in Indianapolis offered the M & W ejectors --
Gus Habich, F.P. Stannard & Moran, Nov. 17, 1906.jpeg
Another maker was C.A. Fischer, Grand Forks, North Dakota, offering ejectors for Parker Bros. guns --
78539 01 Parker Bros. AH 004 C.A. Fischer ejectors.jpg78539 02 Parker Bros. AH .jpg
I seem to recall there was an outfit in San Francisco offering aftermarket ejectors for Parker Bros. hammerless guns as well.
When Parker Bros. introduced their ejectors circa 1901, they were ridiculously expensive at $25 --
Quality D.H. Ejector Catalog.jpg
Ejectors were only $5 extra on Remington Hammerless Doubles.