That's an interesting version of the Defiance zero perfect. Note that the fill is on the back side. There should be a finger loop lift on the front side of the globe plate. The early Defiance zeros copied the Ham side springs, but the most distinguishing characteristic is the orbital guard wire that was later twisted into the 2 piece lift wires to form a globe retaining basket. The models before this one did not have the chisel point tee, so this one would date to circa 1915. The burner cone should be the standard drop-and-turn dimpled cone as winglock cones require a domed fount and were a Dietz patent. BB