Doublewide ID, truss design

[Fran365]

My DW is 24x64, has a massive amount of steel in the crawl supporting the floor, is framed with 2x4s with no headers above windows/doors, was originally sheathed with a black cardboard with aluminum siding. , has very nicely done wiring, ceiling is 16"x 24' panels with a swirl design. I believe it was set up in early to late 80's. My guess is it was set up in 2 halves, roof and all. Can anyone guess the manufacturer? How are the trusses framed? What design do they have? My ridge is sagging and I'd like to know the physics of the whole thing. Fran