Coral 10CX-501 surround

Dear, I have a pair of Coral 10 CX-501 speakers to which I must replace the surround.
The problem is that said surround is something special since it is made of cloth and has the inner edge displaced in height with respect to the outer exterior, I have already tried with standard foam surrounds but the cone is displaced outwards.
If anyone knows where I can get the right replacement I would appreciate it, it's a shame that those drivers are deprecated.
I guess the surround is the same as the Beta 10 uses.
From already thank you very much

Mariano