This is a very rare Webley No.1 Angular Frame revolver in .380CF made in the late 1860's. Webley's No.1 revolvers seem to come in two styles, angular frame like this example, and another style with a rounded grip. They appear to have only been made in smaller calibers - .320CF and .380CF
Angular frame Webley's are also found without the No.1 marking in different frame sizes depending on calibre. Most are marked with just the W&S flying bullet trademark. Very few have the No.1 marking.
This revolver was retailed in Australia by James W. Rosier of 66 Elizabeth Street, Melbourne. There is a small proof mark on the right side of the frame that indicates it was made (or at least proofed) after mid July 1868.
The picture below shows the No.1 Angular Frame Revolver below very similar Webley angular frame revolver in .380CF. This revolver (Serial No.30020) is stamped with the W&S Flying Bullet trademark, but has no other reference to Webley.
Although almost identical there are small but significant dimensional differences between the two.
Below: Four Webley Angular Frame Revolvers.
From top: Webley Angular Frame .442CF (Serial No. 25272); Webley Angular Frame .389CF (Serial No. 30020); Webley No.1 Angular Frame .380CF (Serial No. 29722); Webley Angular Frame .320CF (Serial No. 785).