I'm using the name on one of my favorite French instrument websites, http://luthiervents.blogspot.com.  The name I'm using is a shortened form of what's engraved on the bell:

(Standard Dolnet oval stamp with "DLP")
Dolnet & Lefevre
Brevetés s.g.d.g.
Mantes (S&O)
(Serial number)

"S&O" seems to stand for "Trademark" in France.