NC2 Side Skirt clip conundrum

I am putting a new side skirt on my 2010 NC2 - and have removed the old dead unit.

What I find under the car are a row of 4 or 5 clips with square head in them (so you slot home the base of the skirt), however the one at the very front of this row (at the front of the car) is about half the size of the others, and it has the same square head, just round part for the hole in the car is only about 20mm across, approx 2/3ds the size of the others. And yes you guessed it, that was the only one I broke. (the 4 large ones are grey - this smaller version is black if it helps)

When I look up kits to replace these clips, not one that is listed has this random single slightly smaller sized square head clip available. (so annoying) Can anyone let me in on what the part number is for this bit in particular?

Cheers,

Richard.

NE56-51-SJ3A should be it

Thank you so much.

As you are so brilliant at name that part - do you know what the right screws (hex head) bolts (self tap maybe) are the right replacement for the ones you see when you open the boot, and they screw down on the top deck to the left and right of the numberplate - Mine are rusty as hell of course! There are 2 of them?

9CF6-00-516B
According to Jim Ellis Mazda parts online diagrams.