Thanks, Dan. I'm beginning to get the picture. I'm not convinced that even with new springs, the seats would be comfortable on long trips.
It seems I have two options.
Option 1 - build my interior to look traditional and not be comfortable on long trips.
Option 2 - put comfortable seats in it and not look traditional.
Is that correct? Or, would they be firm and comfortable with new springs and upholstery? I had a '63 Porsche 356 with rebuilt buckets that were very comfortable and as I recall, they were coil spring.