would these pics relate to my 1978 450SEL? (It's not a 6.9)
If i wanted to lower the ride height, is all i need to do - adjust these?
Absolutely. If you've got those components in your car listed in those photos, then you will have self-levelling rear suspension. shortened rod means up - lengthened rod means down
It has no effect on front suspension which is a standard coil and shock absorber setup.
If you look at this thread, http://forum.w116.org/mechanicals/oops-rear-self-levellings-stuck/0/
you'll see how high it can go. It was all sorted in the end. My 350 also sits a bit too high but I still haven't adjusted it.
If you want to lower the rear - keep in mind the lever and valve have a null region of maybe 10o
movement either way before it pumps up or lets down the rear end. So if you lengthen the rod by a few mm's, nothing will happen until you bounce the rear end up and down for a bit with the car running and reveal its new height.
When I try and level my 350, I'll probably remove one end of the adjusting rod, then with engine running I'll move the lever down then neutral, down then neutral, then up if I go too far down, until the car looks level, then reattach the rod adjusted to the right length.