We are going out on a real tangent here Wayne, but I got to say this: Physically it should not be a problem keeping strength and flexibility until well into the 70s or even 80s.
I only have the theory myself as I am 40 this fall.. However I have been weighting more than 110kilos at 178cm. What I noticed was how weak I felt. Endurance was shot. Mobility/flexibility was poor and life was downright heavy. Getting my eating habits under control was the key for me. I feel almost like I did when I was 20 except for the long-term injuries I have collected.
Keeping active and eating properly is in my opinion the key to ageing with full use of the body. Of course the definition of "eating properly" is the crux with opinions, PR companies and scientists pointing in all directions while screaming that they are the only true prophet.

54 years is just the first half smile

You lost me on the Y beam structure I am afraid. How would that look and at the same time reduce drag.

1% for each dagger x 2 = 2%? smile