91 300E will be a W124. It's in the VIN number, starts out WDB124, I think.
You have all the bits for the sway bar there -- four rubber pieces and the bolts and nuts. Only four rubber parts for the W124.
The spreader bar is a bar used to spread the front wheels at the front side when setting the toe to take all the play out of the suspension. McPherson strut systems tend flex a bit under load, and if that flex isn't provided when aligning, the toe won't be correct. Yes, improper toe will cause the car to be excessively sensitive to crown and to follow ridges or ruts. My 300D needs the front done, but I'd not going to align it until I get the other links replace in the back. I had the TE done this summer when I put new tires on it, and it is almost impervious to crosswinds or crowns. Quite a difference.
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!