What's in my stash:
Kit #5827 Copyright 1990 is Case XX
Kit #81160 HM160:2600 was a Hasegawa release of the Monogram kit, Case XX
Kit #5923 ProModeler, Case X
Kit #85-5518, Copyright 2002 Case X
I don't have it but the sprue photos on Cybermodeler show the Case XX wing on the Squadron Encore release. They also say that the ProModeler release has the Case XX wing, but none of the 5 ProModeler kits I have do, all Case X.
The currrent release is 85-5869 and by looking at the instructions on the Revell web site is a Case X. Until I see the sprues I can't be sure, but it may be that Cybermodeler is in error if the instructions agree with the plastic.
If it is the Case XX wing, I'll be happy too, as I have fewer of those in the stash, not that I have any need for more!