The brown object that looks a bit like a wheel I believe is an asbestos laminate 'pad' that was placed between two metal parts to prevent wear on the metal. You need to seal it with clear varnish or something similar. You don't want to be breathing any dust the thing puts out ! I have found very similar items in airbase dumps here in the UK so it is from an aircraft. Do the cartridge cases have any visible headstamps ? They will tell you the nationality of the aircraft.