Oddly enough I just checked the Gunrunners in NV and found both Miss Fortune's and Mysterious Strangers weapons up for sale. Thought those were unable to be used by a player and shouldn't be in the lists. O.o Let me see...
[collapsed title=Hidden text]
FalloutNV.esm=1
DeadMoney.esm=1
HonestHearts.esm=1
OldWorldBlues.esm=1
LonesomeRoad.esm=1
GunRunnersArsenal.esm=1
ClassicPack.esm=1
MercenaryPack.esm=1
TribalPack.esm=1
CaravanPack.esm=1
Fallout3.esm=1
Anchorage.esm=1
ThePitt.esm=1
BrokenSteel.esm=1
PointLookout.esm=1
Zeta.esm=1
TaleOfTwoWastelands.esm=1
SomeguySeries.esm=1
oHUD.esm=1
streetlights.esm=1
NVWillow.esp=1
Children of the Wasteland.esm=1
Lutana CotW Expansion.esm=1
HalfwayHouse.esp=1
CotW Armor Tweaks.esp=1
Cute Shop Armor Tweaks.esp=1
Power Armor Tweaks.esp=1
Cap Raised DR DT.esp=1
The Mod Configuration Menu.esp=1
DLC Weapon Integration.esp=1
PointLookout Tribal Armor for PCs.esp=1
Easy Unlocking and Easy Hacking.esp=1
CASM with MCM.esp=1
Max Level 75.esp=1
Glove_be_gone.esp=1
TTW - Add 4 Eyes to Power Helmets - Overrride.esp=1
ttw_-_custom_race_ending_fix.esp=1
LFox Bottle That Water - TTW Edition.esp=1
AllCompanionsEssential 2.0b.esp=1
Lonesome Road Armor Tweaks.esp=1
PerkEveryLevel.esp=1
XFO - 6aa - Epic Skills - Effects Over 100 (NVSE req).esp=1
PickCompanionArmorandWeapons.esp=1
PipBoyLight.esp=1
TTW_SpeechChecks.esp=1
NewVegasBounties.esp=1
NewVegasBountiesII.esp=1
NoKnockedOverComments.esp=1
TTW_MoreCookingItems.esp=1
TheInheritance.esp=1
Penny_v13.esp=1
The Storyteller.esp=1
NewVegasExtendedMapMarkers.esp=1
GunRunners in the Capital Wasteland 1.1.esp=1
TTW_AnchorageCustomization.esp=1
Cute Shop Vendor in DC.esp=1
HZBagOfHolding.esp=1
FalloutNVCheatTerminal.esp=1
LFox Sink Bug Fixes.esp=1
Movable Milk Crate TTW Edition.esp=1
Faction Armor Converted to Non Faction.esp=1
TTW - Eye Glasses Fix.esp=1
TTW_OutcastTrading.esp=1
TTW_NoKarmaDCFollowers.esp=1
TTW_SuperMutantRebalance.esp=1
TTW Realistic Wasteland Lighting.esp=1
[/collapsed]
Including my load order in case any of the mods is doing it.
http://steamcommunity.com/sharedfiles/filedetails/?id=483266385
And a snapshot showing them in the sales inventory.
