I think you can't remove the nomerge tag because its listed in the file's description (i couldn't)
You need use Tes4Edit to change the file's description i.e. delete nomerge fromthe description field
Wasn't this fixed in WB? You should be able to right-click in the tags frame and uncheck "NoMerge"...right?
A followup to this.
I had this problem too when I installed TT a few days ago, and it bugged me that TravellersItemNpcs.esp wasn't visible active (no + or ?) in Wrye Bash, so I made some tests today.
Building a Bashed Patch without deleting with Tes4Edit, but deselecting it with Wrye Bash (285), does not make it show up in Bashed Patch, 0.txt. No + or ? either
It does however show up in leveled lists when building the patch. I tried deselecting Auto, but that did not make it show up in Bashed Patch, 0.txt either. No + or ? either
The only way I could make it show up in the txt and with a +, was by deleting the NoMerge tag with Tes4Edit.
From the Bashed Patch, 0.txt, without deleting NoMerge (but deselecting it with WB):
Spoiler = Leveled Lists
=== Delevelers/Relevelers
* Francesco's Leveled Creatures-Items Mod.esm [ADR]
* Mart's Monster Mod.esm [ADR]
* FCOM_Convergence.esm [ADR]
* Armamentarium.esm [AR]
* Unofficial Oblivion Patch.esp [ADR]
* Unofficial Shivering Isles Patch.esp [ADR]
* FranDarkSeducerWeapFix.esp [ADR]
* FCOM_Francescos.esp [ADR]
* FCOM_FrancescosItemsAddOn.esp [ADR]
* DLCMehrunesRazor - Unofficial Patch.esp [AR]
* DLCSpellTomes.esp [AR]
* DLCThievesDen - Unofficial Patch.esp [AR]
* FCOM_BobsArmory.esp [ADR]
* FCOM_LothsBluntWeapons.esp [AR]
* Oblivion WarCry EV.esp [ADR]
* FCOM_WarCry.esp [ADR]
* Oscuro's_Oblivion_Overhaul.esp [ADR]
* OOO 1.32-Cobl.esp [AD]
* FCOM_Cobl.esp [ADR]
* FCOM_Convergence.esp [ADR]
* FCOM_RealSwords.esp [ADR]
* FCOM_SaferRoads.esp [ADR]
* FCOM_LessReaversInGates.esp [ADR]
* Mart's Monster Mod - Less Bone Loot.esp [ADR]
* Mart's Monster Mod - Diverse Runeskulls Loot OOO.esp [AD]
* FCOM_HungersUnitySI.esp [AR]
* Mart's Monster Mod - Shivering Isles.esp [ADR]
* MMM-Cobl.esp [AD]
* Knights - Unofficial Patch.esp [AR]
* FCOM_Knights.esp [ADR]
Same, but with the NoMerge deleted with Tes4Edit:
Spoiler = Leveled Lists
=== Delevelers/Relevelers
* Francesco's Leveled Creatures-Items Mod.esm [ADR]
* Mart's Monster Mod.esm [ADR]
* FCOM_Convergence.esm [ADR]
* Armamentarium.esm [AR]
* Unofficial Oblivion Patch.esp [ADR]
* Unofficial Shivering Isles Patch.esp [ADR]
* FranDarkSeducerWeapFix.esp [ADR]
* FCOM_Francescos.esp [ADR]
* FCOM_FrancescosItemsAddOn.esp [ADR]
* DLCMehrunesRazor - Unofficial Patch.esp [AR]
* DLCSpellTomes.esp [AR]
* DLCThievesDen - Unofficial Patch.esp [AR]
* FCOM_BobsArmory.esp [ADR]
* FCOM_LothsBluntWeapons.esp [AR]
* Oblivion WarCry EV.esp [ADR]
* FCOM_WarCry.esp [ADR]
* Oscuro's_Oblivion_Overhaul.esp [ADR]
* OOO 1.32-Cobl.esp [AD]
* FCOM_Cobl.esp [ADR]
* FCOM_Convergence.esp [ADR]
* FCOM_RealSwords.esp [ADR]
* FCOM_SaferRoads.esp [ADR]
* FCOM_LessReaversInGates.esp [ADR]
* Mart's Monster Mod - Less Bone Loot.esp [ADR]
* Mart's Monster Mod - Diverse Runeskulls Loot OOO.esp [AD]
* TamrielTravellersItemsNPC.esp [ADR]
* FCOM_HungersUnitySI.esp [AR]
* Mart's Monster Mod - Shivering Isles.esp [ADR]
* MMM-Cobl.esp [AD]
* Knights - Unofficial Patch.esp [AR]
* FCOM_Knights.esp [ADR]
This Bashed Patch was 3860 bytes bigger than the first. cause for concern, so I compared the two files.
The patch build without deleting NoMerge did not contain the alterations made by TravellersItemNpcs.esp to the second file. I could be mistaken of cause, so someone with better understanding of these things should check.