Okay, I should probably have a changelog.

Notes on the initial development process: https://forums.nexusmods.com/index.php?/topic/4786590-my-attempt-to-fix-darkvision-hit-a-snag/

Modified Item Blueprints:
21_it_kistrelcloak.UTI - Modifies Kistrel's Cloak to provide Darkvision
iprp_feats.2da - Added a line at the bottom that allows the "Bonus Feat" item property to select and grant Darkvision
n2_wsmpku001.UTI - Modifies Kukri of the Eclipse to provide Darkvision
nw_ashmto005.UTI - Modifies Goblin Shield of Nulbish to provide Darkvision
nw_it_mbelt004.UTI - Modifies the Encircling Scale to provide Darkvision
nw_it_novel004.UTI - Modifies the Moonstone Mask to provide Darkvision
x0_armhe017.UTI - Modifies the Helm of Darkness to provide Darkvision
x0_cloth002.UTI - Modifies the Lesser Robe of Eyes to provide Darkvision
x0_mbelt002.UTI - Modifies the Belt of Lions to provide Darkvision
x0_maarcl031.UTI - Modifies Cloak of the Bat to provide Darkvision

Modified Dialogue:
12_edario.DLG - Modifies the dialogue of Edario in Highcliff. His store ID is 12_edario.
20_magic_store.DLG - Modifies the dialogue of Dayne Lynneth, a magic item merchant in A2 Blacklake. His store ID 20_it_st_mages.
20_nwmage.DLG - A dialogue that I don't believe is referenced anywhere, but tries to open 20_it_st_mages. It was corrected, just in case.
21_uncus.DLG - Modifies the dialogue of Uncus in Crossroad Keep. His store ID is 30_it_st_sund_uncus.
31_caelryna.DLG - Modifies the dialogue of Caelryna in Crossroad Keep. Her store ID is 3100_it_st_magic_caelryna.
31_shop_tow.DLG - Modifies the dialogue of the quartermaster, the merchant that spawns in the Tower at Crossroad Keep when it's upgraded. Note that a new store will only be created if you choose to build the NW9 tower.

Modified/Created Store Blueprints (these do not overwrite existing stores - they entirely replace the OC stores, albeit each with a single item blueprint changed):
20_it_st_magesf - A mirror of the store in A2 Blacklake, except with the fixed Cape of the Bat for sale. NeverwinterMagic is the ResRef.
30_it_st_sund_uncusf - A mirror of Uncus's shop in Crossroad Keep, except with the fixed Encircling Scale. UncusSundries is the ResRef.
3100_it_st_weap_nevallef - A mirror of the shop in the NW9 Tower, except with the fixed Kukri of the Night. NevalleWeapons is the ResRef.
12_edario_shopf - A mirror of Edario's shop in Highcliff, except with the fixed Goblin Shield of Nulbish. EdarioShop is the ResRef.
3100_it_st_magic_caelrynaf - A mirror of Caelryna's shop in Crossroad Keep, except with the fixed Helm of Darkness. CaelrynaStore is the ResRef.

New files:
createstore.nss - Uncompiled script that creates store objects from a provided template - Documentation exists if you want to use it yourself
createstore.ncs - Compiled script that creates store objects from a provided template

TO-DO:

Please note that this will NOT affect items already in your inventory, or (I'm assuming) that have already spawned. You can always use the "giveitem" command to get the "new" versions.

If you install this mod while in the middle of a campaign, any of the shops I have changed will have their inventories refreshed when you next visit them.
Any sold items will be unavailable until you remove the relevant .DLG file from your Override folder.

If you have any questions/comments/advice, please message EphemeralBeing on the Nexus Forums. I... might actually see it. Otherwise, /r/NeverwinterNights on Reddit should work.