I am shocked that someone has not mass-produced all-foam seats for theses trucks.
I have read about someone creating them for themselves. I don't remember who it was.
They used a more dense rated foam and used progressively less dense foam on top of the dense layer. Three layers total if I remember right.

1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission