oil filler pipe - two part?

[discipleofsketch]

Because i'm still in denial that my 1Y is burning oil, I spent some time cleaning up various oily parts today to try to identify any oil leaks that might be occuring when the van is moving (still no drips when van is still).

My oil filler pipe has two parts - the metal part that bolts to the sump and a plastic neck, which pushes on and is held on with a clamp:-



Two questions:-

1. should there be some kind of rubber gasket sealing the plastic and metal bits together - this looks a bit crushed when tightened?

2. is this even the right pipe? The replacements i've seen online seem to come as a single unit with the plastic part bonded on, with no clamp.

[discipleofsketch]

oh, I should add - this filler pipe was originally on my 1.6 cs engine, as the 1Y would have been filled from the top..

[discipleofsketch]

OK, from more googling, I've at least established that this is an original 1.6d filler pipe, still not sure about the gasket