It's definitely a WWII-era Webley Mark IV. Look Closely at the photo and you will see "WAR FINISH" marked on the left of the frame. Webley was proud of its commercial-finish guns, and wanted it understood that the finish on these wartime revolvers was an exception and not to its usual standards.

A duplicate of the gun pictured is featured in my book 101 Classic Firearms, on pages 94 and 95.

John

__________________
- Cogito, ergo armatus sum -