Webley pistol

[SPILY]

Hi all, i have just bought this from a gunshop sent dealer to dealer. It was marked as a Webley Senior but on examining it it does not look like a Senior.To start with ,the barrel release lever has a plunger which looks like the Hurricane/Tempest, also near the muzzle appears to be a sleeve on the barrel. The barrel is 61/2 inches and its .22 cal. The grips are black bakerlite marked Webley but no other name is on it. At the front of the cylinder is the numbers 728 which i take to be a batch number.I have photos of it but the site will not allow me to add them. If anyone can please help with the ID i cam mail them.Thanks in anticipation, Paul.
http://s1168.photobucket.com/albums/r490/spily/