I'm working on a translation of a brief article on the "Helice" locking system because I'm pretty sure that "Wonder" lock is a "Helice" copy. The Verney-Carron lock as Larry has said was created in 1896 as an improvement on the Lefaucheux system itself improved by Webley. But it apparently wasn't patented until 1918 by "Helice," a disciple/employee of Verney-Carron, and didn't expire till 1970. And up until 1918 it was shamelessly copied. If this is correct...then the plain Jane I bought has to be pre 1918 because that patent, once registered was pretty zealously enforced.
Model of the lock:
Verney-Carron with a version of the Helice lock engraved from the 1960 catalogue.
Other versions of the lock:
I'll be looking over the shoulder of my gunsmith to confirm my suspicions.
