Sonab OA 14 SC165 spider rebuild

[Fugaziman]

Hi, I'm hoping you folks can help.
I've purchased a pair of OA 14 speakers that I knew needed new foam surrounds. On removing the dust cap on one I found, to my horror voice coil wire poking through. To inspect the damage I've had to cut and remove the spider. The coil can be saved, 3 loops of the wire has become unglued, these I have glued back and tested and all is good. I can source spiders of the correct dimensions but am unsure of what stiffness they should be. Can anyone help and advise please. Many thanks.