Can anyone lend some advice and instruction on how to convert a Tred Avon double into a triple? I'm not needing a full size cockpit in the middle, just something big enough for a small child, but I would like a full size coaming. I'm assuming the rear cockpit moves back "x" amount, and the forward "y", leaving a space in the middle.Any suggestions on these dimensions? At this point I'm not interested in purchasing a new set of plans, or kit, for a different type, I'd like to work with what I already have.