1960-70 Sofa ID assistance please  

Any information/comment regarding the sofa is appreciated. As I have begun to take apart I find it is put together unlike anything I have ever worked with. It is a hardwood frame, Perrelli rubber webbing and large metal brackets attaching the back. The frame is oddly put together and even getting to the webbing to replace has been a challenge. Thank you for looking and any input.

It sounds like Pearsall construction---metal brackets are used to connect the plywood parts of the frame to the more conventional structures. I've never seen that style base with the ends sticking out like that in any Pearsall catalog, though. Maybe it's Pearsall-inspired, included the construction?
Elastic webbing is always stretched across the top of the sofa or chair deck, so you wouldn't be able to get to it without removing upholstery fabric and padding. If this isn't what you meant, please give more details. I know you said you were planning on leaving the brown tweed that covers the deck.

My original plan was to remove tweed fr bottom and lift up to expose decking and padding then access webbing from top, and then replace tweed upholstery. Problem is that tweed is wrapped around a frame that is attached to the frame the webbing is attached too creating a sandwich. So the second frame has to be removed to access decking,padding and webbing. It's not like anything I have seen. So I am going to cut out existing webbing from bottom and attach new webbing to 1"dowel and attach to original frame without removing second frame.

I don't know if that's exactly how Pearsall sofas are made but I do know that they are often partially upholstered before assembly, making it impossible to reupholster them without taking apart the frames. Conventional construction almost always permits reupholstery without undoing any frame sections.
Good luck!