Originally Posted by MBeige

Foam padding will not create a firm surface of support like the original rubberized horsehair padding provides. Been there, done that. Tried the pool noodle approach, and it actually made things WORSE. The cushion was stuffed too much and forced me to roll from side to side.

Found a cheap orange foam pad from a junkyard 300D (1980 or 1981), installed it and have no problems since. Renewed the feel, is cheap (remove at the yard, $10 later you're set). No need to take entire seat unless your springs are broken.



However for the backrest, plenty of the used ones are in horrible shape that new ones are the way to go.