Bousin-Bonnevie (L. N. Bousin & Emile Bonnevie), active in Schaerbeek (one of the nineteen Brussels-Capital municipalities), 1878-1911. The company was assumed by Delheid Frères in 1911.
Hope this helps!
Ref: Walter van Dievoet, Dictionnaire des Orfèvres de Bruxelles au XIXè siècle (Louvain: the author, 2003), p. 54, maker #54.
Blakstone thank for your response! Can you post a scan of the article on Nicolas Luc-(?) Bousin and Emile Bonnevie, from the Dictionary of Goldsmiths of Brussels in the nineteenth century? Thank you again JGL