Just replaced the seat springs in my 83 300 sd. As usual, the left side (door) springs were broken. Found a seat in junkyard. Stripped upholstery and horsehair pad. Lots of new springs-most broken on left side. Drat.
Decided to innovate. Using hammer and cold chisel, opened the slots where springs slide into seat pan. Removed good springs.
Using grinder-lopped them in half.
Open slots on 'my' seat. Removed broken spring halves. Resprung seat with 'new' half springs-reversed from old seat. Closed slots with hammer and chisel.
Used steel wire to wrap/reinforce all joints and tied most of the
springs together to distribute load more evenly. Reinstalled foam
pad. Seat feels great. Will reinstall upholstery in am.