Thomas, Beautiful work on the center section. Moving along really well, my projects tend to plod along due to work/daughter schedules. I wanna be quicker- like you! lol
With that much wing area, I think cubic loading will be working in your favor greatly. I predict that she will not only fly very well, but that you will be pleasantly surprised at the glide ratio and slow speed/low throttle setting flight.
My 82" model is 8 Lbs. yet glides beautifully. If you look at my video closely, you can note some periods of low throttle flying and throttle off glide. At one point you can faintly hear my friend ask "what's that, about half throttle?" and me respond, "no that's off".
Did you ever get a hold of the Bentley drawings? He has a full website: