Are those coins really from FJ casino or did you hide the details here about tainted source coins that you had be dealing with and used FJ as a "mixing" mode or a transit wallet to cover up your tracks? Most of the newbies posting such threads, I would not trust without having head both sides of the story. Bitstamp has been here for long time and them asking KYC with such strict details does make me wonder what juicy information they have obtained on the coins.
You may try to present a story in your way of describing but this is what I suspect has happened.
Wow this is quite inflammatory. Yes it's legitimate winnings at fortunejack. I deposited something like 0.5 btc and withdrew 36 btc in total. If you work for fortunejack like your avatar suggests you would know which account I am as there was a big fuss about that in that fortunejack themselves did extensive kyc and asked me to send Apostilled identification and other things before finally releasing my winnings...
And now this from bitstamp, it seems every company in the crypto space is at it.