I haven't finished the game yet, so please don't spoil anything in your answers :)

This post contains (minor) spoilers from the probably mid-to-late parts of the game though, so don't read if you haven't played it.

When I was back in Congo with Nico in the room with spikes (very Indiana Jones-y) I got Nico across by putting the rod into the gears. Then I just moved on without checking the corpse that was lying there. But apparently there were some item(s) on this corpse, such as an emblem of some sort, and I think a metal item too.

Do I need these items later in the game, or am I fine to continue?

Thing is, I have played on a bit further so not sure I have a savepoint from here. Have only been using 3 saves :( And due to the stuff I have cleared now it's almost certainly impossible to trace my steps back.

Edit:
Oh never mind. Thankfully had one from just after a certain maze thingy so was able to backtrack from there and get it sorted.