Projects Split back bench upholstery

Hey all, need some help. Got a 54 ford customline im redoing the interior on. Its all ezboy ( or lebarron bonney ) stuff. Does anyone know how to install covers on the split backs for the front bench? Looks like the covers just roll under the bottom edge and tuck into a seam, but what holds them there? Im gonna tear the existing cover off and see what i can find. Also theres stainless trim on the seat backs, anyone know how they attach ? Heres a few pics of the seat backs





And heres some shots of the rest of the interior thats pretty much finished up

 

Before you put the panels on, the windlace goes on first.