I'll buy three with an option for a fourth.

I agree. I'd even say it makes the bird even more impressive given how well it was reported to have flown. It means he balanced all the engineering propeller-head stuff (yes, that was an intended pun) so that the final ratios of the wing span, wing surface area, weight of the aircraft and forward speed all worked together to produce the perfect aerodynamics and handling. I studied the stuff for 4 years and earned my degree and I bet neither I nor half of my graduating class would have got it that right. The man's a wizard in my books.Several of you commented on thinking it would be bigger, which got me to wondering. It seems like he down-scaled it a bit, in consideration of the maximum work area he had. The real bird's wingspan is 103 feet. His model, at 4m/13.12ft, is a bit short of the 5.23m/17.16 ft wingspan for 1:6 scale.
Which makes that bird no less impressive to me.