Update: my Coolscan 9000 sad story has just ended, in the most unexpected but happy way!
Out of sheer kindness, someone made an exception and sent me an original replacement FPC for the Coolscan

I carefully (but quite nervously) installed it and only after the second attempt, the Coolscan sprang to life!! What can I say. I am overjoyed and really very grateful !
There are still beautiful things in this troubled world, such as this act of kindness.
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By the way, a member of fb Nikon Scanner Users group has recommended a generic FPC that is said to be compatible with this Coolscan FPC. I have ordered it through Digi-Key but have not tried nor verified it to be working personally. I shall list the info. here just in case anyone who might need to find such a replacement part:
Molex part number 0151660429
Thanks everyone here for all the great advice/suggestions. Much appreciated.
yossi