My moms Olds was made into a Buick with different badge's. My dad just replaced the rear struts with some from Napa because the orignals blew out. Frankly I was amazed how cheap these things are I am used to $70 Bilsteins!
Anyway the ride is soft but not like you described. Since you got the car for free I'd replace the shocks I think you will be more happy with it.