Just use andi06's LNER Gresley triplet and restaurant stock. It can be toggled to be color you're looking for; they'll look much better than using the TGV coaches.
Search "andi06" under "Locomotives." They're made for TRS09, so they should work for you.
They can be toggled to be in the silver livery with the streamlined valances.
Goodness, edh6 already suggested this. Nobody has to reskin anything this way.