Grete Jalk 118 Sofa & Matching Chair by France and Sons Webbing?  

Welcome to the forum, Divot. Looking forward to seeing your photos!

Photos would be good, but if you somehow have an empty frame foundation then that would be unfortunate. It was done with eeeee springs then a layer of polyurethane foam, then a fabric coverlet that was wrapped around the frame and attached in the inner edges. 

I hope you can see this picture

Thank you for your response Leif.  This is the base I have for the sofa. It appears to have some residue of foam? on it and it has been stapled with 17 one inch straps at some point in time.  I am a woodworker and I can make a new base when I am no longer sequestered in the house.  As this is for my living room vs resale, I would love some advice on the best approach to create a base and decking materials.  A picture of the chair with the square base I have for it should be attached here. 

Is the base broken or damaged in some way? Is it really necessary to make a new base?

If not you can still get the original springs, they would originally be fastened with a U shaped tacks. The springs run front to back at approximately every other centimeter.

I've seen plenty of sofas with later added webbing used as the owner could not source the original springs, this works fine.

Welcome back, HM. How are things in the UK these days?

Thanks cdsilva, all good here, hope you are well too.

Stuck inside like most of the rest of the world. At least I have managed to do some jobs around the house I have been putting off for the last 9 years! Time certainly does fly. I've been gone from the forum so long I am now a new member.

To the OP, I will recap some of what has been said. You have the correct foundation frames. The first step is new eeee spring which @mcm-interiors post (hi!) and as he said they are put in with large staples, not sure where to source those, but the hardware stores probably have something about right for affixing wire or cords. Next is a thin layer of polyurethaning foam over the whole top, maybe 1/4 inch thick. Next is a medium weight fabric coverlet. France always used a specific fabric, google around for images. This fabric was wrapped all the way around the frame to the inner edge and staples in place there with typical upholstery staples. 

Thank you so much. That makes perfect sense to me given what I have and what was left on the foundation frame. I've cleaned up the frame and will keep it. I really appreciate knowing what I should do.  In the interim, I purchased a webbing tool and some elastic webbing for upholstery.  I haven't tried to do that myself but if I am not feeling that I'm doing a good job I will go with the eeee springs. I've got the cushions ordered. The only thing that I have left, that I might as well ask you, are the rubber? washers that I had between the frame and the metal frame supports.  Were these special in any way?  What I have is almost completely eroded.  I also read that I should use the same screws? Mine are flat heads which are my least favorite.  I'd love to know your thoughts. Thanks again!

I've never seen a washer between the metal frame supports and the frame. Perhaps someone added these as the screws they had found to use were too long?

You could source any appropriate length wood screw to do this job, washer or no washer. Good luck with it.