Well, Johhny Turk fought the Brits on several Fronts, not least in Arabia: the turks could have taken quite a number of guns when the British suffered their big disaster at Kut Al-Amara.
That could be my pics of the HIH 10,5 cm howitzer. Indeed converted 18pdrs, with more than just the breechblocks altered: a Rheinmetall howitzer boxtrail carriage, a barrel bored out to 10,5cm and crew seats to the shield, see here: http://www.network54.com/Forum/330333/message/1152282073/Introducing+the+1930+Turkish+Vickers-HIH+gun!