You may be able to get some replacement springs from the vendor below.

http://www.snydersantiqueauto.com/search.php?q=seat+springs&x=0&y=0

Keep in mind that each spring row has springs of different height and number of coils. If I recall correctly, the wire diameter of the perimeter springs are heavier gauge than the center springs.


1941 Chevy 1 1/2-ton WW2 4x4 dump truck
In the Stovebolt Gallery
Lots more pictures