My dears, I need brainstorming help. So, for the artifacts, I have several options, and I hope one of these gives one of you guys a nice idea for something, or well, mainly our GM.

[b]A)[/b] the missing [url=https://en.wikipedia.org/wiki/Second_Temple]Menora[/url] from the second temple. 
[b]B)[/b] A piece of the [url=https://en.wikipedia.org/wiki/Ark_of_the_Covenant]Ark of the Covenant[/url], for example one of the angels or something. 

If our lovely GM would like it Egypt-related, he would say that it was found/excavated in Egypt.

Though, after everything that happened there, would Thierry allow Theo to go to such a place? I'd assume he'd only not block trips to very safe sights. 

[b]C)[/b] is the [url=https://www.dawn.com/news/1079617]Missing Giza Cap[/url], which is very on the nose though. 

In a waaay different corner would be
[b]D)[/b] Chinese: [url=https://en.wikipedia.org/wiki/Heirloom_Seal_of_the_Realm]A Chinese missing imperial seal[/url]
[b]E)[/b] French: [url=https://en.wikipedia.org/wiki/Scepter_of_Dagobert]French Scepter of Dagobert[/url] (Maybe most realistic for Theo? + Maybe it's a wieldable weapon that Galloes comes to steal)
[b]F)[/b] Belgian (close enough): [url=https://en.wikipedia.org/wiki/Ghent_Altarpiece]The missing pannel from the Ghent alterpiece[/url]

For the foreign artefacts we could say that they'll be returned to the original country and yay international friendships made by the Louvre. 

I think I'm most on board with.... E.