Seriously though, I imagine it's either a misplaced file, or a feature of the new haks. If its the latter, just buy some clothes. If its the former, I would assume that one of our tech admins/builders would know.
Some pretty much unavoidably displaced existing models, usually bumping their numbers upward in the toolset. A great majority of them though added to the "end" of any given list of models, such that there'd be no displacement/replacement. Also a number of female-only models came into the list, which are "invisible / null" if on a male PC/NPC.
You would seem to be a victim.
Self help would include:
(1) Retooling your armor in the toolset, to your taste, and getting DM import help, or
(2) Using a tailor shop (Sembia definitely has one) to try some new looks for the legs... possibly restoring your old ones. The tailor scripts seek things by different numbering systems than the toolset, so I'd be pretty confident you might get back to how you were. Cost of tailors IG is pretty nominal. If you found yourself completely bankrupted by self-helping, DMs might take some mercy too, giving you a tailor budget OOCly.
I am not sure if there's any hak-related help planned or forecast on this, again, I know some of the models unavoidably shifted, maybe some of them though, there's other ways to manage model numbers to minimize the problem. I don't know, my understanding on some of the alterations is surfacey.
ALFA NWN2 PCs: Rhaggot of the Bruised-Eye, and Bamshogbo
ALFA NWN1 PC: Jacobim Foxmantle
ALFA NWN1 Dead PC: Jon Shieldjack
there is a particular style of tailor in SD and NC that will alter your existing outfit for you, retaining all plusses, bonuses or what have you. That is the most painless way to fix.
Last PC: Laurelin ~ dancer, trickster and professional pain-in-the-backside
If you still have this armor, could you equip it, save a local copy of your character and email it to me? (pretty sure I have an email addy on the profile) If it was literally a "I updated, now my thighs are gone." situation, it probably means there's a leg model hiding somewhere, and having numbers will make tracking it about a million times easier.