SS/B Barracuda project

Stefan here is some measurement's taken from a 66-69 A-100 seat frame. Should help you get your frames to size.
Height from table to top of backrest is 20 3/4"
Height from table to tack strip is 5"
I took a close up of the tack strip attached to the lower rung.
This is where the backrest cover will staple to the frame.
It is a paper/tar type material but a strip of hardwood could
be used to work better.