Hi,
Here’s a link to the [https://media.needapart.co.nz/manuals/MDR-1000X%20Consumer.pdf|parts manual] for your headset.
Unfortunately there is no further information as to what the individual part numbers relate to in this diagram.
If you can identify the part (and its’ associated part number) from the parts list, try contacting the [https://www.needapart.co.nz/buy-online/parts-for/sony-mdr-1000x|supplier] using the online email form at the bottom of the webpage to see if they can help.
Hopefully this is of some help.