AAAgh!!! Not again!!
L Brown. I suggest you do read the posting and the replies.
The name for the part in question was taken from a Webley & Scott parts list from the 1970s yes! They did supply some parts and castings, given to me by a local Gunsmith.
Now if yo you read the description of how the action opens and closes it is obviously not the description of a genuine screw grip action.
Gunman has kindly given the correct factory name for the said top leaver surround in one of his replies for which I am grateful.
Oh!!!! Please can we put this to bed because I am starting to feel that firstly I wish I had not put pen to paper as the say secondly I have the feeling this screw grip thing, which was not my naming of the part is going to follow me around every time this posting rears its head like the chains of Marley's ghost.
Damascus, sorry I didn't wade through all the posts. From "The History of W. & C. Scott Gunmakers, by Crawford and Whatley (p.69): "Both Model 400 and 500 guns were fitted with the Webley Screw Grip, a type of rib extension patented by T.W. Webley in 1882." Most of us with some familiarity with British doubles are familiar with the screw grip. Unfortunately, it likely WILL haunt you. If someone referred to a Model 700 as a screw grip gun in Double Gun Journal, poor Dan Cote would find himself buried under a pile of letters and emails. And I know how you feel. Narrowly escaped that fate myself when I did an article for Shooting Sportsman about proof, chamber length, pressure, etc. I used the standard formula for converting a pressure measurement in bars to psi. Unfortunately, the proofmaster informed us, even though the British were by then marking proof pressure in bars, they were still working off old lead crusher pressure readings rather than piezoelectronic transducers. I think it was all an evil British plot to confuse your cousins across the Pond!
Fortunately, we corrected the numbers and provided an explanation before the story ran.
