I'm considering a Druine Turbi, and some advice given in response to my intro post was to make sure I'd fit before launching into a project. Makes scary sense. I acquired a set of plans that show the inside width of the rear cockpit as 576mm, or 22.6 inches (the frame behind the cockpit is 610 mm, with a 17 mm longeron on each side). That's about the width of my shoulders. I wouldn't want to be rubbing on the sides, and also would need some more room if wearing a jacket. My question for those of you with design experience is whether I would be opening an unjustifiably big can of unintended consequences by adding somewhere between two and four inches to the center of the spars and fuselage to create a little more clearance. I really like this design, but if I couldn't be reasonably comfortable I should keep looking for a design that suits me better. Thanks.