This is most definitely a Webley screw grip, as identified by the "horseshoe" on the top lever.
You can get a copy of the A&N ledger for a specific A&N number from the Glasgow University for a small fee.
The Webley numbers are different from the Scott numbers before the merger in the late 1890s.
The Webley guns sold by others usually bear the Webley number on the foreend loop.
I hope this helps.
WC-

Last edited by WildCattle; 08/26/18 11:07 AM. Reason: typo