Roy,
In the updated version (1985) of Don Zutz's book "The Double Shotgun" there is a section in the chapter on French guns dedicated to Vouzelaud. Mr. Zutz was quite clear in stating that all the Vouzelaud guns were boxlocks, and in the book is a photo of the twin to the above gun, stating the gun is a 315-EGL that looked "exactly like a fine sidelock", and that the screwheads and the axles are false.
The line of Vouzelaud guns at that time was three obvious boxlocks and two bearing decorated, but, false sideplates.
The information in the book dovetails exactly with what I saw in France a decade later. The Vouzelaud guns I handled were A&D boxlocks.
The name engraved in the barrel is that of Thomas E. Humphrey, a successful builder from Indiana, and benefactor to the NRA. Mr Humphrey passed away in 2013, and while I never met him, I knew of him-he had contact with other French builders that I also did. I am fairly certain that this is the late Mr. Humphrey's gun.
It is NOT information to comply with BATF (Not "Customs") law pertaining to the marking of imported firearms. This gun seems to have missed that legality, which, happens from time to time, but, not as much as it used to-BATF stepped up examination for compliance with that requirement while I was still in the business. I had a few go through without it, however.
Best,
Ted