Caps for a metal turret roof with a gable end

I have a roofing contractor who is installing ribbed metal roofing on a turret similiar to the home pictured on your web site on line tour. The problem is that it is not a full turret. The turret is more like a multi-surfaced gable end. He can not satisfactorily finish off the peak of the turret so that it looks finished. Is there any type of cap or finished product that I can advise him to use. I can send a jpg. image of the roof if needed Thank you for any assistance you can give me in this matter.