This auction by Waffen-Dumbeck is still running. The gun is certainly more than worth its present bid. However, I understand your question to be an inquiry whether specifically *this* style of dealer inscription would be typical and proven for any weapon sold through a branch shop of Lebeau-Courally ? The actual maker might be a smaller artisan thus ?

Also, the auction smells at least a bit of shill bidding.

Carcano