Tannoy System-1000 7900-0406 Replacement HF Diaphragm

Looking for Tannoy 7900-0406 Replacement HF Diaphragm
Hi all. I have a pair of passive Tannoy System 1000 speaker. One of which has a very tired HF Diaphragm I know they have been discontinued so if anyone knows where I can buy such a beast, I will be eternally grateful.

Please help....
 
That’s the 10” poly DC right? Could it be using the same HF as the 8” used in many of their speakers like S8/S10 D500/900 etc? Not sure how to find out though but I thought these diagrams was standardized for a lot of their product lines. Try to find what other speakers use the same and then look for them second hand.