Yes kdanie, the strength is a concern for me to, but they are storng for now, we will see how they will hold mounted on the car.I've had sparco and momo seats and I will compare them to this seats.Basically, they can hold me with no problem(I weight over 250 lbs/ 95 Kgs).
As for padding, I am working on it, hope they will look good and be confortable, but the fiberglass is the most important. I just can't wait to finish one of them....
For sizes, they should be the same as this momo seat:
A
mm/inches =590 mm/ 23.2"
B
mm/inches=340mm/13.4
C
mm/inches=530mm/20.9
D
mm/inches=510mm/20
E
mm/inches=390mm/15.3
F
mm/inches=290mm/11.4
G
mm/inches=500mm/19.7
H
mm/inches=880/34.6
Hope this helps.
Martin