The CK prefix is the standard IGT item number while FES appears to be for limited release or give away items and is not necessarily IGT specific. I think it might stand for festival, and seems to be related to seasonal trade shows in Japan (maybe a fun time to get together and laugh about how they get all the good stuff?). The windscreens were made available again in 2016 under the FES- numbers, and are readily available on yahoo japan auctions as well as amazon.co.jp (although not for direct shipping to the USA). I've used a proxy service to order a windscreen and other hard to find items. There are a few different options, but fromjapan.co.jp is the one I used and I have been very satisfied with the service.
My order was also cancelled. They are apparently redesigning it for release in October.
View attachment 412042
Replaced grill with cast iron griddle plate. Also made some adjustment to the regulator.
They also delayed that water dispenser...
https://www.snowpeak.co.jp/sp/notice/notice_GS-355_UG-153.html