Show us your XML.

i scrapped the code already but essentially what i did to start was nab the alchemist that gives potions to the shop... out of coreimprovements.xml and changed it so....

    <ImprovementType InternalName="ArmsDealerBuilding">
        <DisplayName>Arms Dealer</DisplayName>
        <Description>Random Text.</Description>
        <RequiresCity>1</RequiresCity>
        <BarredTerrain>River</BarredTerrain>
        <BarredTerrain>SwampTerrain</BarredTerrain>
        <PreferredTerrain>City</PreferredTerrain>
        <PreferredTerrain>Category:Land</PreferredTerrain>
        <PreferredTerrain>Forest</PreferredTerrain>
        <Prereq>
            <Type>AbilityBonusOption</Type>
            <Attribute>ArmsDealers</Attribute>
            <Target>Player</Target>
        </Prereq>
        <LaborToBuild>10</LaborToBuild>
        <GameModifier>
            <Provides>Random Text.</Provides>
        </GameModifier>

       <UnlocksShopItem>RandomItem01</UnlocksShopItem>

       <UnlocksShopItem>RandomItem02</UnlocksShopItem>

        <AIData AIPersonality="AI_General">
            <AIPriority>10</AIPriority>
            <AITag>Merchant</AITag>
        </AIData>
        <ArtDef>Art_BlackMarket</ArtDef>
    </ImprovementType>

Then for coreabilities i just used the enchanter base since it gives unique building in the scrying pool...

    <AbilityBonus InternalName="ArmsDealerAbility">
        <AbilityBonusType>Player</AbilityBonusType>
        <AbilityBonusOption InternalName="ArmsDealers">
            <DisplayName>Arms Dealers</DisplayName>
            <Description>Random Text.</Description>
            <Icon>Combat_Dot.png</Icon>
            <GameModifier>
                <Provides>Random Text.</Provides>
            </GameModifier>
            <Cost>1</Cost>
            <HideWhenUpgraded>0</HideWhenUpgraded>
            <Type>Army</Type>
            <AIData AIPersonality="AI_General">
                <AIPriority>5</AIPriority>
            </AIData>
        </AbilityBonusOption>
    </AbilityBonus>

the Arms Dealer shows up in the custom faction choice screen, but when starting a new game the building isnt in the build list.  So im either missing something somewhere or just being a noob....  im assuming im just completely missing an entry in some other file

From the code you posted I've got the arm dealer faction trait... restarted the game... then created a sovereign from that faction and I get the arms-dealer building in my build options.

I haven't tested the unlock RandomItem01 or 2 but I know that works from using it from my buildings I've done. That code looks fine to me.

ho hum...  what the heck then....   i'll toss them into the actual core files quick   see what happens

yeah that randomitem01 was just goin to be the item internal names of my items wanted to test...  just tossed that down for the sample

EDIT:  yeap works now   musta messed something up having them in their own files in the mod folder...  thanks for checking it guys appreciate it... guess im not as hopeless as i thought lol.

any idea why they may not have worked putting them in their own seperate files in the mod folder?

either that or maybe the initial code was crap and by scrapping it and redoin it quickly to show you guys i actually fixed whatever minor issue i had the first time?   lol   so finicky,  yeah tossed them back into mods folder...  still works, so must have fixed the initial problem by starting over again to show the code to you guys lol...   thanks