The foam inserts were an idea I got from this site. They are in fact solid foam like from round exercise rolls and cut to shape. Pretty hard. In fact too hard. I was going to remove them but pushed them forward instead. I like them there because it gives great lateral side support at the front corners. Where as before, the corners would dive down too much. It also supports the rear just a bit. In the prior position at the rear as shown, it was so stiff it literally angled you forward.
Yes, the diaphragms work just fine. The mechanism was apart and I cleaned and adjusted it before installing the seats. Diaphragms are available but from a later car and you have to refit them. A PAIN but doable. These are original diaphrams. The whole system is very vunerable from damage underneath. Most people would never assume something this intricate is under there.
Not sure where to buy the chrome part. The classic Center MIGHT have it. Other than that just salvage yards.
