IWC Warranty/ID Card?
Discussion
Can't help on the card front but regarding selling I would try in the classified section on here, one of the numerous dedicated watch sites like TZ-UK (though you need to be an active member for a bit before you go selling stuff) and I'd even suggest eBay. Believe it or not, I've had a couple of successful, hassle-free sales on there which included a 1980s Tudor that went to Italy and a Breitling for Bentley which I sold for £2k.
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