SS Tie Fighter parts ID

Hi all.
I would be greatly appreciative if someone could tell me which donor kit parts contribute to the region I've circled in the attached photo of a Studio scale ILM Tie fighter prop.
I haven't been able to find any clear photos of this section of an ILM Tie, so I'm struggling to make out what this region actually looks like.

Many thanks in advance.

I can't help with the ID, but here's a better pic.

I believe it's a railing from a Heller ship.The 2 square pieces may be scratched?I'm not 100% sure though.

Dave