I have been looking at a Webley & Scott from the same era, albeit a lower grade gun. The one I have been looking at has a straight extension, not a doll's head, but it does not look like the one above. It has an angled notch cut into the extension, rather than the "shelf?" in the one above. This gun does have a locking screw set into the main top lever screw, but I cannot see any screw threads in the spindle. Are all of these guns screw grips? Were there different versions of the screw grip action? I have heard reference to Model 400s and 500s.