Apparently I am a bit violent when I open the lid, as some of the screws and nuts have came loose. And by come loose I mean came undone and fallen to their death either inside the unit or outside in the grass, never to be found again.
So right now the lid is on by two screws (one in each of the hinges).
I can take a nut and a screw to the hardware store and ask for a new one. Is there any materials I might want to avoid?
For the washer, that is a different scenario. The ones that came with it don't seem to be that high of quality. I have noticed they have started to crumble. Would a plain metal one work or does it need to be made of something special?