These are RS parts, but they do work on airsoft from what I know, so I am posting them here. They are both practically new, I shot 10 rounds through my shotty with them on.
Remington 870 synthetic full stock
Remington 870 sytnhetic pump
Both for $50
STI parts off my 1911
Govt length wood grips book matched (from what I can see) Hand checkered double diamond wooden grip panels, Philippine Mahogany $40
Screw set flat head $8
Pictures will be up shortly.