What makes you think the Konor was built by Webley & Scott? As far as I know, Cogswell & Harrison made all their own boxlocks. The Konor, I believe, was a post-WWII boxlock made at C&H's Park Road Works in East Acton, London W3.
C & H didn't make this one. Original Birmingham proof marks, no London marks present. Yeah, date code is for 1957, as the serial number appears to be as well. There is no evidence of reproof or rebarreling present, as the water table does not have a view mark, which would have been present from earlier (pre-1955) proof. The photo of the barrels shows the last digits of a non-matching serial number, which is normal for a Birmingham trade built gun. The trade makers usually stamped their serial numbers somewhere on the underside of the barrels. If C & H built the gun themselves, there would be no non-matching number here.
Birmingham marks, non-matching number on the barrels, London maker's name - standard for a Birmingham gun built for the London trade.
