Frayed seat belt.

We have a 2014 Roomster. The driver’s seat belt is frayed at bit where it passes through the buckle when in use. It was flagged as an advisor the last MoT test. I have no doubt it is not going to break but what I do know is how bad can it be before it fails an MoT. Does anyone have knowledge or experience of this please.

I am looking for the part number for the belt. I have found a part number for an early date but I am unsure if it would be right for a 2014. I thought the Roomster was based on a much older Fabia and I sort of doubt they would change the seat belt design .

anyone out there got part numbers? 
 

Thanks