[Yukyuk]

Thank you again Seerah.

Took me a few more hours, but it worked.
I now have the guild banner in my addon.
Ended up using the "SpellBookSkillLineTabTemplate".



Few more things to do to make it "perfect".
The first time it displays the no_guild logo instead of the guild banner.

And at the top left of the guild banner you see the original texture.
<Texture file="Interface\SpellBook\SpellBook-SkillLineTab"> from the "SpellBookSkillLineTabTemplate".
Is there a way to remove that?

 <CheckButton name="SpellBookSkillLineTabTemplate" virtual="true" hidden="true">
        <Size>
            <AbsDimension x="32" y="32"/>
        </Size>
        <Layers>
            <Layer level="BACKGROUND">
                <Texture file="Interface\SpellBook\SpellBook-SkillLineTab">
                    <Size>
                        <AbsDimension x="64" y="64"/>
                    </Size>
                    <Anchors>
                        <Anchor point="TOPLEFT">
                            <Offset>
                                <AbsDimension x="-3" y="11"/>
                            </Offset>
                        </Anchor>
                    </Anchors>
                </Texture>
            </Layer>