Hooked Quilon Sanderson 1907 Bayonets

Is anyone able to provide a date, as precise as possible, when Sanderson stopped manufacturing the 1907 bayonet with the hooked quilon, please? Ian Skennerton gives a date of 29th October 1913 as an official approval date for this modification in his book "British and Commonwealth Bayonets". I assume that it was a number of months after this date when the bayonet manufacturers actually put the change into practice and started producing the 1907 bayonet without the hook? I have a 1907 bayonet by Sanderson dated Nov. 1914, without a hook, that is currently stripped down for cleaning and restoration/preservation. Thanks for any information.

British 1907 bayonet with quillon dated 11/13