The Ercol 364 is not so common model, the back cushion fitting just between the wings very comfortably.
We've done quite a few seat only 364's. Some people prefer to see all the lovely frame on the 364.
The second picture below shows the fixing tapes in place, these prevent the back cushion from sliding about.
These cushions are available in any of our 5000 available fabrics. Shown here in our Camira Mid Grey Stitch.
Cost without piping:- Seat from £105 Back from £90