Seatbelt help needed please

[Dannyb6467]

Hi folks,
Just come to fix a duel seat in place but the buckle is hanging free....any idea how or where it fixes to please?

 

[Dannyb6467]

I have realised what I need....does anyone know what part number this is please?

 

[DanW81]

The locking plate 7H5857328
Bolt N98924904