Engine bay

[Mark D]

Hi everyone,
  Starting to do a bit of a tidy up in the engine bay of my '72 lowlight...fuel tank breather hoses etc. and I'd like to replace the heat shielding on top of the bay, but I'm little confused by the fasteners holding it up. What exactly are these things? some sort of pop rivet?

   

And is this material available anywhere? Also, does anyone know where I can source this cover?

   

Thanks for any help,

                                        Mark