You may remember a post I made a little while back regarding some items I've been considering selling. I've listed one of these items today on eBay. As far as I'm aware it's a pretty rare cassette...
http://www.ebay.co.uk/itm/251546468294?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2648 (http://www.ebay.co.uk/itm/251546468294?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2648)