Can anyone please confirm for me what the part number is for the forged extractor on a regular, right handed 12 gauge 870. Also, is the one extractor spring that is available in the Remington online store the only one I need? I am also then wondering when people normally replace extractors on an 870. Are they like a Glock's extractor, where you pretty much only replace it if it becomes chipped or starts to show signs of obvious damage; and begins to not successfully extract fired shells? Are there any function tests to know if the extractor plunger spring is sufficiently strong? I am going to start putting together a little emergency spare parts kit for my 870, and I think that these two parts are going to be the first ones purchased. Thanks!